To test whether models trained in one cell type can be applied in other cell types, we first used the model trained in GM12878 CTCF ChIA-PET to predict loops in the human chronic lymphocytic leukemia cell line K562 (~500 million cis-reads)8 and in mouse embryonic stem cells (1.9 billion cis-reads)51. This evidence concerns the gene CTCF and B-cell chronic lymphocytic leukemia.