Here, we analyzed the expression of LOX-1 in human breast cancer tissues in relation to the classical prognostic factors strictly connected to the therapeutic treatment (estrogen receptor/progesterone receptor (ER/PR), HER-2) characterizing the role of LOX-1 and its splice variant Δ4, in vitro, in the neoplastic context of three different molecular phenotypes (MCF-7, MDA-MB-231, SK-BR-3). The gene discussed is PGR; the disease is breast cancer.