Identification and prediction of breast cancer subtypes is a wide and highly investigated research field. Many research groups have identified and reported subtype specific signatures. Common to many of these signatures is the supervised approach where specific phenotype associated features are provided as input. We identified TFAP2B in an unsupervised approach and show that the expression correlates with two distinct subgroups of luminal breast cancer which are not identical with Luminal A/B subgrouping. Though several publications describe the association of AP-2α and AP-2γ with breast cancer, AP-2β ist still hardly investigated in the context of breast cancer. Here we investigated the TFAP2B correlations and show that TFAP2B is associated with the WNT/ß-catenin signaling pathway.