passages.id: split_5_test_1709_passage
passages.type: progene_text
passages.text: p16 ( INK4a ) is an important negative cell - cycle regulator , but in contrast with a wide range of malignancies where inactivation of the INK4a gene is one of the most common carcinogenetic events , in PV p16 ( INK4a ) expression was dramatically increased without a significant change in ECFC cell cycle compared with normal ECFCs .