Epigenetic silencing of the APM may be the relevant mechanism of immune escape in SCLC, and it has been shown that epigenetic modulation can increase MHC I expression in SCLC [25, 32, 33], whereas expression of the epigenetic regulators EZH2 and LSD1 has been shown to be inversely correlated with outcomes with immunotherapy [21]. This evidence concerns the gene KDM1A and small cell lung carcinoma.