PGR and breast cancer: Initial cell proliferation assays were performed with dilution series (0-100 μM) of DHA and CCM using four breast cancer cell lines and one line (MCF10AT) representing 'premalignancy', each with a unique pattern of cellular receptor expression: SK-BR-3 (ER- PR- Her2+), MDA-MB-231 (ER- PR- Her2-), MDA-MB-361 (ER+ PR- Her2+), MCF7 (ER+ PR+ Her2-) and MCF10AT (ER+, PR isoform B but not A, Her2 variable).