In the Oncomine and TCGA databases, there were nine genes among the PPPCs family that were differentially expresssed in breast cancer tissues compared with normal breast tissues (elevated expression of PPP1CA, PPP2CA, PPP4C and PPEF1 and reduced expression of PPP2CB, PPP3CA, PPP3CB, PPP3CC and PPP6C). This evidence concerns the gene PPP3CA and breast cancer.