MDM4 and breast cancer: In a second meta-analysis of three GWAS including 4,193 ER- breast cancer cases and 35,194 controls, combined with 40 follow-up studies, variants at rs4245739 located in the 3′ region of the mouse double minute 4 homolog (MDM4) oncogene on chromosome 1q32.1 seemed to be specific to TNBC [16].