NOTCH1 and embryonal rhabdomyosarcoma: To test the function of ICN1 in human ERMS, we next performed knockdown of NOTCH1 using three different short hairpin RNAs (shRNAs) in RD and SMS-CTR cell lines, both of which are ERMS, have activating RAS mutations, and express high levels of ICN1 (Figures 3D–3H and S3G–S3J).