AR and breast carcinoma: A significant proportion of cells (~30%) indeed had an AR of less than 1.5 and likely represent a distinct phenotypic population in addition to the elongated, more phenotypically mesenchymal-like single cells, which is consistent with previous observations that heterogeneous cancer cell phenotypes with significant plasticity exist in breast carcinoma and PDA and undergo 3D migration by contact guidance (10, 11, 27, 36, 37).