In particular, we observed tumor-specific genetic alterations in PTPN21, PTPN23, PTPN5, PTPRA, PTPRE and PTPRS whereas mutations reported by Wang et al. were confined to PTPRF, PTPRG, PTPRT, PTPN3, PTPN13, and PTPN14. This difference most probably can be explained by the different screening strategies used in these two studies. The gene discussed is PTPN21; the disease is neoplasm.