We conducted differential gene expression to further characterize the NEUROD1-high (abbreviated ‘NE-variant’) and ASCL1-high (abbreviated ‘NE’) clusters observed with RPM cells (from cell lines and tumors) and found that the NE-variant cluster was associated with increased expression of genes highly expressed in variant SCLC (NEUROD1, SCG3, IGFBPL1, SSTR2, and MYC) (Figure 4—figure supplement 1D, Supplementary file 1). The gene discussed is IGFBPL1; the disease is small cell lung carcinoma.