These cell lines carry a BRAF mutation (Colon Cancer Panel 2, BRAF; ATCC No. TCP-1007), but the HT-29 cells also carry a mutated p53 gene (G→A mutation at codon 273 resulting in an Arg→His substitution, R273H) causing overproduction of a pathogenic form of p53, while SW48 cells have a wild-type allele. The gene discussed is BRAF; the disease is digestive system cancer.