To investigate whether proliferative defects induced by loss of SNRPD2, SNRPD3 and NHP2L1 were TNBC and/or cell line specific, we performed knockdowns of these factors in four additional highly proliferative breast cancer cell lines covering different breast cancer subtypes (MDA-MB-468 and HCC1806 are from the TNBC basal A subtype, while T47D and MCF7 are from the luminal subtype). Here, SNRPD3 is linked to breast cancer.