CSF1R and tenosynovial giant cell tumor, diffuse type: A recently developed CSF-1R inhibitor, PLX3397 (or Pexidartinib), which is orally potent and can cross the blood–brain barrier, is currently designated as a ‘Breakthrough Therapy’ by the FDA for the treatment of tenosynovial giant cell tumour (TGCT) and other solid tumours [17].