BRAF and melanoma: Furthermore, there were signs of positive selection in case of BRAF mutant melanomas during metastatic progression from the primary tumor, since medium to high (6/32), low to medium (3/32) and low to high (7/32) MAF shifts of metastases were more prevalent (16/32, 50.0%) as compared with the high to medium (3/32), medium to low (3/32) and high to low (1/32) MAF alterations (9/32, 28.1%).