It has been reported that calpain-2 (CAPN2) regulates invadopodia and breast cancer invasion [48], promotes tumor growth and the proliferation of cancer cells in the mammary carcinoma through PI3K-Akt-FoxO-p27(Kip1) signaling [49], and is required for glioblastoma cell invasion [50]. This evidence concerns the gene CAPN2 and cancer.