Considering the MMTV-like env negative BC samples, APOBEC3A/B deletion is negatively correlated with tumor stage (Tau-c = −0.151; p = 0.044), while in MMTV-like env positive BCs, APOBEC3A/B deletion positively correlates with ER (Tau-b = 0.179; p = 0.041) and shows a strong negative correlation with patients age-at-diagnosis (Tau-c = −0.382; p = 0.009). The gene discussed is APOBEC3A; the disease is breast cancer.