The rhogap19d phenotype resembles the early steps in breast cancer. (A) Images of breast tissue samples reproduced from Halaoui et al. (2017; Fig. S3), reprinted with permission from Genes & Development, showing examples of FEA and ADH. Samples were immunostained for Par-6 (red), E-cadherin (E-Cad; green), and DAPI (blue). The white arrows show polarized cells invading into the lumen. The yellow arrows show epithelial bridges that split the primary lumen. (B)rhogap19d mutant cells (marked by the absence of RFP), stained for E-cadherin–GFP (Cad-GFP; green) and DAPI (blue), show similar apical bulges and invasions to FEA and ADH. Cells first bulge apically (white arrows in the left panel), then start to collectively invade the germline (white arrows in the middle panel), to finally form big clusters inside the egg chamber (white arrows in the right panel). Stage 8 egg chamber. Experiment repeated five times. Scale bars, 10 µm. (C) Kaplan-Meier survival plot for ARHGAP21 expression (high; top quartile versus low; bottom quartile) in bladder carcinoma. Survival data were retrieved from the kmplot resource (kmplot.com) described in Györffy et al. (2010). (D) Kaplan-Meier survival plot for ARHGAP23 expression in lung adenocarcinoma. HR, hazard ratio, with 95% confidence limits in parentheses.