We thus chose the SUM149PT cell line to assess the role of ERRα in the biological behavior of VDR in a representative model of triple negative, inflammatory breast cancer falling within the most aggressive basal‐like subtype of BC (BLBC), and the MCF7 cell line for the same purpose in a Luminal A breast cancer model that is less invasive and aggressive. The gene discussed is ESRRA; the disease is breast carcinoma.