Virtual screening allowed for the identification of phidianidine A (257) as a potential ligand for CXCR4, a chemokine receptor involved in several diseases, including cancer progression, metastasis, and immunodeficiency disorders, and competing with natural ligand CXCL12 as observed by molecular docking, proving that it is a CXCR4 antagonist [608]. The gene discussed is CXCR4; the disease is cancer.