A family of inhibitors of cyclin-dependent kinase 4 which act as tumour suppressors. The family includes p14ARF (ARF here is ‘alternative reading frame’), p15 (INK4b), p16 (INK4a), p18 (INK4c), and p19 (p19ARF, INK4d) which is induced by vitamin D and by retinoids and blocks the ubiquitin-ligase activity of mdm2 from targeting and inactivating p53. Mutations in p16 are more common in tumours than mutations in p53. See also CIP/KIP.
Subjects: Medicine and Health — Chemistry.