We analyzed the association of Δ133p53α, Δ133p53β, and Δ133p53γ with the current clinico-pathological subtypes of breast cancer: luminal A (ER+, PR+, HER2-), luminal B (ER+, PR−, HER2-), luminal/HER2+ (ER+, PR+/-, HER2+), HER2 positive (ER-, PR-, HER2+), and triple negative (ER-, PR-, HER2-), according to the recommendations of St Gallen International expert consensus (Goldhirsch et al., 2013). This evidence concerns the gene ESR1 and breast cancer.