ERCC4 and xeroderma pigmentosum: We also examined the growth rate of yeast with mutations in other NER genes (RAD1, RAD4, and RAD14, which are the yeast homologs of XPF, XPC, and XPA, respectively) that cause XP but not CS (Kraemer et al., 1987; Kraemer and DiGiovanna, 2003 (http://www.ncbi.nlm.nih.gov/books/NBK1397)).