PAIP2 and head and neck cancer: By analyzing the data from the public database, RT-qPCR and Western blotting, we clarified that PAIP2 was highly expressed in breast cancer cells and breast cancer tissues at mRNA and protein levels, compared with normal breast cells and adjacent tissues, which was consistent with the high expression detected by previous researchers in human head and neck cancer (Onesto et al., 2006), suggesting that PAIP2 had potential value as a diagnostic biomarker for breast cancer.