MCM5 and small cell lung carcinoma: Furthermore, the expression of MYC downstream targets, including LDHA, HK2, MCM5, and CDC7 was markedly reduced upon CUDC-907 or CUDC-907 combined with olaparib treatment in MYC paralog-amplified or overexpressed SCLC cells and tumors (Supplementary Figs. 2 & 5).