RRM2 and cancer: CKS2 (chr9q22.2), CEP55(chr10q23.33), UHRF1 (chr19p13.3), RRM2 (chr2p25.1), AURKA (chr20q13.2), FLJ39632 (chr14q11.2), FAM83D (chr20q11.23), NEK2 (chr1q32.3) and MAD2L (chr4q27) were all located on PCSRs and showed over-expression in the 9, 8, 10, 9, 8, 9, 9, 8 and 9 types of cancers, respectively (Table 2 and Table 3).