MARK2 and cancer: There are three unique subtypes of RAF kinases in addition to homologues of BRAF.22–24 Many studies concluded that the BRAF serine/threonine kinase alterations have been detected in various types of human cancers that are linked to cell growth, survival and differentiation.25 BRAF gene (V600E) is the most abundant type of BRAF mutation in human cancers because of substitution of a valine for glutamic acid at position 600.