Supporting evidence includes (1) studies that have shown that BRAF mutations occur more frequently in areas of intermittent sun exposure than areas of chronic sun exposure [34, 44]; (2) the fact that the V600E mutant lacks a classic UV signature [42]; and (3) reports that have characterized V600E mutations in CMN that developed in utero  [12]. Here, BRAF is linked to congenital mesoblastic nephroma.