MCF10A series progressively acquires basal-like microenvironment characteristics. (A) One-dimensional (genes only) hierarchical clustering showing interaction scores (I values) for genes that significantly change due to coculture. Distinct clusters of genes are upregulated in each cell line. A gray bar adjacent to the heat map shows a cluster of genes that are uniquely upregulated in the MCF10DCIS:RMF cocultures. (B) A basal-like interaction score was developed previously by Camp and colleagues ; the coculture data show a strong relationship between progression and expression of basal-like microenvironment characteristics. Luminal cocultures had a negative basal-like interaction score, while the score increased with progression from A/AT1 to ductal carcinoma in situ (DCIS), with DCIS having interaction scores similar to those in the basal-like invasive cancer cell line SUM149. ANOVA, analysis of variance; RMF, reduction mammoplasty fibroblast.