Also at pre-clinical stage, PRT543 on Splicing factor 3b subunit 1 (SF3B1) uveal melanoma MEL202 (SF3B1R625G active mutant) and MEL270 (SF3B1WT) cell lines showed downregulation of SF3B1 target genes associated with increased intron retention, predominantly in the MEL202 mutant. The gene discussed is SF3B1; the disease is uveal melanoma.