One of the two cases considered the mechanisms of LCNEC transformation may be inactivation of TP53 and Rb1, which were similar to SCLC transformation.[104] Moreover, Shinichi et al. pointed out that EGFR T790M-positive ADC had rare APOBEC-associated mutation, which can promote SCLC transformation. This evidence concerns the gene RB1 and small cell lung carcinoma.