For example, gemcitabine targeting RRM2 are validated for the treatment of non-small-cell lung cancer,50 ovarian cancer,51 pancreatic cancer,52 adrenocortical cancer,53 and oral squamous cell carcinoma.54 We speculate that gemcitabine can be used to treat bladder, colon, kidney, liver and prostate cancers. This evidence concerns the gene RRM2 and oral cavity squamous cell carcinoma.