STK4 and neoplasm: In mammals, the core Hippo pathway is a kinase cascade comprised of the sterile 20-like family kinases serine/threonine protein kinase 4 (STK4) (also known as MST1) and STK3 (also known as MST2), the large tumour suppressors (LATS1 and LATS2) and the adaptor proteins Mps One Binder kinase activator (MOBs) and Salvador homologue 1 (SAV1) [11].