Using microarray analysis, Shimizu et al. found that let-7 miRNAs negatively regulate B-cell lymphoma 2 like protein 1 (Bcl-Xl) expression and can induce apoptosis when used with an anti-cancer drug targeting myeloid cell leukemia sequence 1 (Mcl-1) in human HCC (79). The gene discussed is MCL1; the disease is cancer.