NR4A1 and breast cancer: In contrast, we [37] and Adebamowo et al. [54] reported lower frequencies of basal-like BC subtype (as defined by triple-negative, basal CK+ phenotype) in Sudanese (10%) and Nigerian BC series (15.8%), which was mainly due to the markedly higher frequency of hormone receptor positivity found in these tumor series (Sudan: ER: 64%; PgR: 67%; ER and/or ER: 75%, Nigeria: ER+: 65.1%; PgR: 54.7%), as compared to the other studies from Africa [33–37, 54].