KRAS and non-small cell lung carcinoma: The most frequent mutations in KRAS mt NSCLC are transversion mutations involving guanine to thymine or guanine to cytosine nucleotide changes, such as glycine 12 to cysteine (G12C) accounting for 41%, followed by glycine 12 to valine (G12V), both associated with a history of smoking, whereas transitions mutations, involving guanine to adenine nucleotide changes, such as glycine 12 to aspartic acid (G12D), are found mainly in never smokers (4).