CISH and cancer: Two TIL clinical trials to treat gastrointestinal cancer involve the collection of TILs from patient tumors and enhancing their antitumor efficiency through knock out of the gene Cish. TILs capable of targeting gastrointestinal cancer cells have been found in patients [38]; however, Cish, a member of the suppressor of cytokine signaling (SOCS) family, has been shown to block the avidity of the TILs and reduce their activity against cancer [39].