BCR and cancer: To verify that Hi-C faithfully detects proximity of known translocation loci, we first examined the canonical translocation partners BCR and ABL, which form an unbalanced, often-amplified rearrangement in the K562 human cancer cell line (Figure 2A) and have been shown by FISH to colocalize in the nuclei of multiple normal hematopoietic cell types prior to the translocation event [9], [21].