ABCB7 and myelodysplastic syndrome: In addition, we performed RT-PCR for ABCB7 in K562-SF3B1K700E and SF3B1WT isogenic cells obtained using CRISPR/Cas9 gene editing and the pancreatic cell line Panc 05.04, which has a heterozygous SF3B1 K700E mutation, and we observed the same ABCB7 cryptic 3′ splice site event (Figures 4c and d), which introduces a stop codon as identified in the CD34+ cells and cultured erythroblasts of SF3B1-mutant MDS patients.