KRAS and cancer: While genomic alterations in the RAS genes are less frequent in primary breast tumors compared to other cancer types, it is interesting to note that gain-of-function mutations in KRAS or HRAS and their downstream effectors are found in TNBC cell lines that are claudin-low and most commonly used in cancer research (e.g., MDAMB-231, Hs578T, SUM159PT) [109].