Effect of shRNA-mediated NRL knockdown in NRL expressing cells (D458MED, HDMB03 and three MB PDXs (PDX1–3)) or in non-expressing cells (DAOY and ONS-76). shRNA control (Ctl,black) and two shRNAs targeting NRL were used (shNRL#1 and shNRL#2, red) as indicated. (A, C) Apoptotic content measured by FACS analysis of cleaved caspase 3 and (B) viability assessed in PDX1–3 (Cell titer Glo Promega). Each experiment was performed in triplicate. Bars represent the mean ± SD. The p value was determined by unpaired t test. **p-value < 0.001, ***p-value<0.0001.