MYO1E and neoplasm: While we observed no obvious differences in the localization of structural components of cell-cell junctions in the MYO1E WT and MYO1E KO tumors (Supplementary Figure 2) and isolated tumor cells (Supplementary Figures 3, 4), the accumulation of fluid in MYO1E KO tumors and the fact that these tumors retained two cell layers typical of mammary ducts (Figure 3) indicate that cell-cell junctions is these tumors are more stable and less permeable to water.