To reveal the possible correlation between GRAF1 levels and cancer cell phenotype, we assessed GRAF1 expression levels in 7 different cell lines, all of breast cancer origin: invasive MDA-MB-231, MDA-MB-468, MDA-MB-435, and SUM-149, which preserved an epithelial-like morphology, MDA-MB-436 and BT-549, characterized by a polymorphic morphology, and the non-invasive neoplastic MCF7 line (Supplementary Table 1). The gene discussed is ARHGAP26; the disease is breast carcinoma.