Polymorphisms found in tumor suppressors and cell cycle regulators have also been identified, such as p53 SNPs in nonfunctioning PAs or cyclin D1 in prolactinomas.
MIB-1 (Ki-67) overexpression was also highly associated with increased acetylation of H3K9, correlating prositively with tumour severity (P < 0.0001). p53 overexpression had a contributing effect on altered global H3K9 acetylation of atypical pituitary adenomas (P < 0.05).