Clinically, this provides a basis for investigation into the use of IMPDH inhibitors such as MPA and mizoribine, but also may in part explain why anti-folates and nucleoside analogues are moderately successful in NEUROD1 and POU2F3-expressing SCLC, which commonly exhibit MYC overexpression (78, 80). Here, NEUROD1 is linked to small cell lung carcinoma.