CLDN3 and neoplasm: Within this predominantly basal tumor type, cells with features of AvPs (BRCA1-4) were also present with elevated levels of Cldn3, Malat1, Krt18, Wfdc18 and Mfge8. Once again, the extensive heterogeneity within these BRCA1-null tumors were apparent along with the genes and pathways for each of these clusters (Figure 4—source datas 1–2).