CSK and neoplasm: Examples of caspases acting in a tumour-suppressor role occur in epithelial tissues containing scrib, rok, mud, Sin3a, Snr1, Csk, or frazzled mutant cells [125, 141, 166–168] or overexpressing a subunit of the Vacuolar ATPase (V-ATPase) complex, Vha44 [169].