Transcriptional analysis reveals that NNMT, a key regulator for the intracellular concentration of SAM,[21, 33] is the most down‐regulated metabolic gene in OXPHOS‐sensitive cancer cell lines compared with the resistant ones (Figure 3A; Figure S3A, Supporting Information), implying a possible correlation between NNMT expression and cancer cell sensitivity to OXPHOS inhibition. The gene discussed is NNMT; the disease is cancer.