TSC1 and lung carcinoma: To identify previously unidentified immune modulators, we performed a CRISPR screening in a murine KrasG12D/Trp53−/− (KP) lung cancer model (C57BL/6 background) (6) and found that tuberous sclerosis complex subunit 1 (Tsc1) and subunit 2 (Tsc2) as potent regulators of Pd-l1 expression and sensitivity to PD-1 blockade treatment.