PTBP1 and melanoma: Similarly, in cutaneous melanoma, brain metastasis is predetermined by CD44 splicing variant 6 (CD44v6), whose expression correlates with PTBP1 and U2AF2 splicing factors, and especially, PTBP1 knockdown significantly decreases CD44v6 expression in advanced melanomas [44]; their binding motifs match to KER_269 and KER_842, respectively.