XIRP2 and cancer: Though few studies have investigated roles of BPIFB2, XIRP2 and NELL1 in GBM, all the three genes may have potential roles in other cancers. BPIFB2 has been reported to be overexpressed in gastric cancer, which may result in expression alteration of epithelial-mesenchymal transition (EMT) markers [23], and XIRP2 has been shown to be frequently mutated in lung adenocarcinoma [24].