fusion

An ALK fusion, usually EML4::ALK, is a swapped piece of chromosome 2 that turns the ALK kinase on permanently in about 4 percent of lung adenocarcinomas. Seven ALK inhibitors are approved for it, including alectinib after surgery.

The fusion that defines chronic myeloid leukaemia and a quarter of adult acute lymphoblastic leukaemia; the first cancer driver ever switched off by a pill.

A gene fusion that drives an aggressive leukaemia in infants and adults. It cannot be blocked directly, but the scaffold protein it depends on (menin) can.

An NTRK fusion joins one of three TRK kinase genes to a partner and drives cancers from infant fibrosarcoma to salivary and thyroid tumours, rare in common cancers but near-universal in a few rare ones. Larotrectinib, entrectinib and repotrectinib are approved for it regardless of tumour type.

RET fusions drive 1 to 2 percent of lung cancers and some thyroid cancers; RET point mutations drive medullary thyroid cancer. Selpercatinib is approved for RET fusions in any solid tumour and for RET-mutant medullary thyroid cancer; pralsetinib for RET fusion lung cancer.

A ROS1 fusion drives about 1 to 2 percent of lung adenocarcinomas and behaves much like ALK. Crizotinib, entrectinib, repotrectinib and taletrectinib are approved for it.