RNA sequencing revealed that the neuroendocrine markers such as NEUROD1, NCAM1, ASCL1, CHGA, INSM1, SYP were either absent or weakly expressed in LUAD and T-LUAD, whereas these transcription factors were robustly expressed in both T-SCLC and SCLC (Figure S3C). Here, SYP is linked to small cell lung carcinoma.