To validate the assumption that GPR55 participates in the DHA-DA cytotoxicity independently of the cell line, we tested the cytotoxicity of the substance on a panel of human cancer cell lines, chosen to represent different tissues: breast cancer MDA-MB-231, glioblastoma U-87 MG, pancreatic cancer PC3, PANC-1, and DU-145, colon cancer SW620, and a nontumorigenic epithelial cell line MCF-10A. The gene discussed is GPR55; the disease is breast cancer.