Cell line morphological, genetic, and functional characteristics.

Cell line aggregate morphological classes, cancer stem cell (CSC) percentages, subtypes, positivity for wound, hypoxia, and 70 gene signature, and collagen related activities.§CSC percentages obtained from Ref. [50]. MDA-MB-468 cells were not included in this study and thus labeled N/A (not available).*Subtypes of breast cancer cell lines identified by unsupervised hierarchical clustering: BB = basal B, BA = basal A, L = luminal [21, 46].**Subtypes of breast cancer cell lines using tumor cell classifications described in Ref. [43] as reported in Ref. [46]: ERBB2 = ERBB2 signature; B = basal, LA = luminal A, LB = luminal B. ***Subtypes of breast cancer cell lines using tumor cell classifications as reported in Ref. [47]: CLL = claudin-low; B = basal; L = luminal.++ = positive and— = negative for wound or hypoxia gene signatures or poor prognosis signature in the 70 gene assay as reported in Ref. [46].#This study: + indicates moderate to high collagen contractile capacity (Fig 5), moderate to high levels of collagen-relevant integrins (Fig 4), and capacity to efficiently invade collagen I gels from spheroid culture (Figs 3 and 5).Cell line morphological, genetic, and functional characteristics.