These disruptions are often caused by structural variations or damaged CCCTC-binding factor (CTCF) interaction due to changes in DNA methylation.403 The proto-oncogene TAL1 is activated by microdeletions that obliterate TAD boundaries in T-ALL.403 Broken genomic insulation in gliomas and gastrointestinal stromal tumors interferes with CTCF anchoring at loop structures. Here, CTCF is linked to gastrointestinal stromal tumor.