NECTIN4 and breast carcinoma: To verify that the effects of PVRL4 depletion are not limited to SUM190 cells, we expressed anti-PVRL4 shRNAs in two additional breast cancer cell lines, Sk-BR-3 and BT-474 (Figure 6—figure supplement 5), which both express lower levels of PVRL4 than SUM190 cells (Fabre-Lafay et al., 2007), and observed a strong defect in clonogenic growth (Figure 6—figure supplement 6) and reduced proliferation in the absence of anchorage (Figure 6—figure supplement 7).