GRM8 has been identified as an ASCL1 and NEUROD1 ChIP–seq target in human SCLC cell lines52, and expression of GRM8 correlates with the expression of ASCL1 in cell lines reported in SCLC-CellMiner53 and is reduced in autochthonous SCLC mice in which Ascl1 is deleted specifically in cancer cells12. Here, GRM8 is linked to small cell lung carcinoma.