INK4 is a tumour suppressor protein. It is associated with several genes, including p16INK4a and p14ARF

P14arf

p14ARF is an alternate reading frame product of the CDKN2A locus. Both p16INK4a and p14ARF are involved in cell cycle regulation. p14ARF inhibits mdm2, thus promoting p53, which promotes p21 activation, which then binds and inactivates certain cyclin-CDK complexes, which would otherwise promote...

, and with several other proteins, like HRAS

HRAS

GTPase HRas also known as transforming protein p21 is an enzyme that in humans is encoded by the HRAS gene. The HRAS gene is located on the short arm of chromosome 11 at position 15.5, from base pair 522,241 to base pair 525,549.- Function :...

. Lack of this protein has been associated with several types of cancer, including bladder and melanoma. The 'INK4' label is given to three proteins: INK4A and INK4B. These proteins act to inhibit cdk4 and cdk6 upon binding, causing the arrest of the cell cycle in G1.