In prostate cancer, SEMA3A is overexpressed in tumour tissue and is associated with the recruitment of monocytes and their polarisation into M2 macrophages, which are associated with resistance to androgen deprivation therapy, whereas, in breast cancer and glioblastoma (GBM), SEMA3A recruits antitumour macrophages. The gene discussed is SEMA3A; the disease is breast carcinoma.