The updated 5th WHO classification of Tumours of the Urinary System and Male Genital Organs has also recently introduced a molecularly defined group of renal tumours including TFE3-rearranged RCC, TFEB-altered RCC, ELOC (formerly TCEB1)-mutated RCC and SMARCB1-deficient medullary RCCs, signalling a transition to a novel integrated diagnostic approach rather than morphology-based diagnostics [6]. The gene discussed is TFE3; the disease is renal cell carcinoma.