RET and small cell lung carcinoma: Previous studies have documented that the sustained overexpression of both mutant M918T and wild-type (WT) RET in SCLC cell lines results in the excitation of MAPK/ERK (mitogen-activated protein kinase/extracellular signal-regulated kinase) signaling, upregulation of MYC expression, and enhanced cellular proliferation, with mutant RET exhibiting a more pronounced effect.