As reported in the paper entitled “Suppression of KRas-mutant cancer through the combined inhibition of KRAS with PLK1 and ROCK” [9] in a recent issue of Nature Communications, we developed a synthetic lethal drug screening with a combinatorial strategy using a panel of clinical agents, and we identified several unique genotype-selective synergistic drug pairs that selectively killed KRAS-mutant cells but spared untransformed ones. This evidence concerns the gene PLK1 and cancer.