ASCL1 and small cell lung carcinoma: Recent studies demonstrated that MYC activates Notch signaling, driving the temporal evolution of SCLC heterogeneity by conducting the sequential conversion of SCLC tumor cells from an ASCL1- to a NEUROD1- and, ultimately, to a non-NE (YAP1) state (Fig. 3a) [47, 86–88].