PROK2 and lung cancer: To explore the clonal expansion pattern in TIL, five specimens from lung cancer patients were selected for immunoscope (CDR3 length polymorphism) analysis, and seven TCR subfamilies (BV3, BV7, BV8, BV13, BV16, BV17, and BV21) overexpressed in TIL of lung cancer patients were selected to show the CDR length distribution (Fig. 4).