Tumor suppressive function of NF1 (neurofibromatosis type 1) in several cancer types including melanoma [6–8], DAB2IP in prostate cancer [9], RASAL2 in breast cancer [10], PLXNC1 (Plexin C1) [11] and RASA2 [12] in melanoma have been described. This evidence concerns the gene PLXNC1 and breast cancer.