Structurally, ABL’s N-terminal domain is exchanged with BCR’s coiled-coil domain, wherein the coiled-coil drives ABL kinase oligomerization and renders it constitutively active.6 The Catalogue Of Somatic Mutations In Cancer (COSMIC), a carefully compiled mutation database, covers genes fusions known to be involved in cancer, as defined in the Cancer Gene Census. Here, BCR is linked to cancer.