Although we found that mutations or deletions of the GMNN gene were not prevalent in human cancers, the R54Q mutation in geminin protein was detected at a high frequency, and other potentially significant sites that may be phosphorylated under different circumstances are Thr25, S32, S60 (Tsunematsu et al., 2013) S45, and S49 (Kulartz et al., 2003), although the physiologic relevance of these modifications remains to be determined. This evidence concerns the gene GMNN and cancer.