The findings presented here and in our previous report14 show that the reversible K-Ras(G12D) inhibitor KS-58 can suppress the growth of tumors derived from PANC-1 pancreatic cancer cells and CT26 colorectal cancer cells expressing K-Ras(G12D) without serious side effects such as weight gain/loss, liver pathology, or kidney dysfunction. The gene discussed is KRAS; the disease is colorectal cancer.