ESR1 and cancer: In order to analyze whether the genes encoding ABPs are preferentially expressed by certain cancer subtypes, differential mRNA expression analyses were performed for lymph node status (N0: no lymph nodes are affected; N1: at least one lymph node is affected), estrogen receptor status (ER+/−: estrogen receptor-positive/negative) and the molecular subtype at baseline (luminal, HER2-positive, triple-negative breast cancer).