| Non-Controlling Interests | 
     |    13.   |    Non-Controlling Interests   |         
 Non-controlling interests in consolidated entities, as recorded on the Condensed Consolidated Balance Sheets are as follows:        |       |        |    As of June 30, 2018   |        |     |       |        |    NCI Equity Share   |        |    Net gain/(loss) attributable  to non-controlling interests   |        |    Non-controlling interests  in consolidated entities   |        |    Non-  controlling  ownership   |        |     |   Aevitas   |        |    $   |    (407)   |        |    $   |    (184)   |        |    $   |    (591)   |        |        |    37.0   |    %   |     |   Avenue2
   |        |        |    12,865   |        |        |    (9,631)   |        |        |    3,234   |        |        |    64.5   |    %   |     |   Caelum   |        |        |    (2,121)   |        |        |    (1,474)   |        |        |    (3,595)   |        |        |    33.9   |    %   |     |   Cellvation   |        |        |    (418)   |        |        |    (91)   |        |        |    (509)   |        |        |    21.6   |    %   |     |   Checkpoint1
   |        |        |    24,543   |        |        |    (9,482)   |        |        |    15,061   |        |        |    67.5   |    %   |     |   Coronado SO   |        |        |    (290)   |        |        |    -   |        |        |    (290)   |        |        |    13.0   |    %   |     |   Cyprium   |        |        |    (183)   |        |        |    (50)   |        |        |    (233)   |        |        |    10.8   |    %   |     |   Helocyte   |        |        |    (3,203)   |        |        |    (91)   |        |        |    (3,294)   |        |        |    19.8   |    %   |     |   JMC   |        |        |    (459)   |        |        |    165   |        |        |    (294)   |        |        |    6.3   |    %   |     |   Mustang2
   |        |        |    37,669   |        |        |    (6,729)   |        |        |    30,940   |        |        |    60.0   |    %   |     |   National Holdings   |        |        |    15,805   |        |        |    (3,628)   |        |        |    12,177   |        |        |    43.4   |    %   |     |   Tamid   |        |        |    (164)   |        |        |    (110)   |        |        |    (274)   |        |        |    24.0   |    %   |     |   Total   |        |    $   |    83,637   |        |    $   |    (31,305)   |        |    $   |    52,332   |        |        |        |        |                |       |        |     As of December 31, 2017   |        |     |       |        |     NCI Equity Share   |        |     Net gain/(loss) attributable  to non-controlling interests   |        |     Non-controlling interests  in consolidated entities   |        |    Non-  controlling  ownership   |        |     |   Aevitas   |        |    $   |    (126)   |        |    $   |    (168)   |        |    $   |    (294)   |        |        |    35.4   |    %   |     |   Avenue2
   |        |        |    17,454   |        |        |    (4,646)   |        |        |    12,808   |        |        |    66.1   |    %   |     |   Caelum   |        |        |    (815)   |        |        |    (1,262)   |        |        |    (2,077)   |        |        |    34.7   |    %   |     |   Cellvation   |        |        |    (259)   |        |        |    (96)   |        |        |    (355)   |        |        |    21.5   |    %   |     |   Checkpoint1
   |        |        |    21,635   |        |        |    (12,314)   |        |        |    9,321   |        |        |    62.0   |    %   |     |   Coronado SO   |        |        |    (236)   |        |        |    (54)   |        |        |    (290)   |        |        |    13.0   |    %   |     |   Cyprium   |        |        |    (143)   |        |        |    (15)   |        |        |    (158)   |        |        |    11.1   |    %   |     |   Helocyte   |        |        |    (1,907)   |        |        |    (1,193)   |        |        |    (3,100)   |        |        |    20.0   |    %   |     |   JMC   |        |        |    (469)   |        |        |    7   |        |        |    (462)   |        |        |    6.3   |    %   |     |   Mustang2
   |        |        |    48,740   |        |        |    (11,911)   |        |        |    36,829   |        |        |    61.6   |    %   |     |   National Holdings   |        |        |    17,021   |        |        |    (1,216)   |        |        |    15,805   |        |        |    43.4   |    %   |     |   Tamid   |        |        |    (6)   |        |        |    (92)   |        |        |    (98)   |        |        |    24.0   |    %   |     |   Total   |        |    $   |    100,889   |        |    $   |    (32,960)   |        |    $   |    67,929   |        |        |        |        |              |   (1)   |    Checkpoint is consolidated with Fortress’ operations because Fortress maintains voting control through its ownership of Checkpoint’s Class A Common Shares which provide super-majority voting rights.   |            |    (2)   |    Avenue and Mustang are consolidated with Fortress’ operations because Fortress maintains voting control through its ownership of Preferred Class A Shares which provide super-majority voting rights.   |       
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