RRM2B and carcinoma: ZongLin Deng,s reported newly identified polym-orphisms in the p53R2 gene,It was found that the 3 ‘end of the p53R2 gene had three gene polymorphisms and one gene polymorphism at the 5’ end, which could increase the risk of carcinoma [31].Before the formation of cancer cells, p53R2 provides dNTPs for DNA repair and increases the expression of p21while decreasing the expression of cyclin D in wild-type p53 cell to arrest cell cycle in order to repair damaged DNA.