In colon cancer cells, 5-FU is predominantly converted to ribonucleotides via OPRT [53] (encoded by UMPS), and in SCLC the downregulation of TYMP coupled with moderately upregulated UMPS (log2FC = 0.37; Supplementary Table S2) is consistent with 5-FU also being predominantly converted to ribonucleotides. The gene discussed is TYMP; the disease is small cell lung carcinoma.