EGFR and small cell lung carcinoma: Integrating the EGFR driver mutation, the contaminant TP53 and RB1 mutations (38, 39), and the use of gefitinib, the multi-omics analysis method suggested that LU2E, a SCLC sample, was likely to result from the histological transformation rather than the development of a primary lesion, even though there was no molecular feature information of LU2C.