a. The A and G alleles of rs1053036 in NR_125431 are cis-linked to the A and G alleles of rs3748136, respectively. Linkage model is based on TLA mapping. This locus in K562 cells is most likely triploid. b. Fraction of reads containing each of the two alleles of SNP rs1053036 in NR_125431 in K562 genomic DNA (left) and K562 RNA-seq reads (right). P-value was obtained by a one-sided Fisher exact test. The complete lack of expression of the A allele of NR_125431 is unexpected and may point to a genetic defect of the A allele in K562 cells. c. Clonal lines derived from K562 cells show extreme expression variation of NR_125431. For CRISPR-based editing we proceeded with clone BL_2.