Component of HBO1 complexes, which specifically mediate acetylation of histone H3 at 'Lys-14' (H3K14ac), and have reduced activity toward histone H4 (PubMed:16387653). Through chromatin acetylation it may function in DNA replication (PubMed:16387653). May inhibit tumor progression by modulating the transcriptional output of signaling pathways which regulate cell proliferation (PubMed:15251430, PubMed:15528276). Can suppress brain tumor angiogenesis through transcriptional repression of RELA/NFKB3 target genes when complexed with RELA (PubMed:15029197). May also specifically suppress loss of contact inhibition elicited by activated oncogenes such as MYC (PubMed:15029197). Represses hypoxia inducible factor's (HIF) activity by interacting with HIF prolyl hydroxylase 2 (EGLN1) (PubMed:15897452). Can enhance apoptosis induced by serum starvation in mammary epithelial cell line HC11 (By similarity). Homodimer (PubMed:19187765, PubMed:22334692). Component of the HBO1 complex composed of KAT7/HBO1, MEAF6, ING4 or ING5, and one scaffold subunit: complexes containing BRPF scaffold (BRPF1, BRD1/BRPF2 or BRPF3) direct KAT7/HBO1 specificity towards H3K14ac, while complexes containing JADE scaffold (JADE1, JADE2 and JADE3) mediate acetylation of histone H4 (PubMed:16387653). Interacts with H3K4me3 and to a lesser extent with H3K4me2, the interaction augments KAT7/HBO1 acetylation activity on H3 tails (PubMed:16728974, PubMed:18381289). Interacts with EP300, RELA and TP53; these interactions may be indirect (PubMed:12750254, PubMed:15029197). Interacts with EGLN1 (PubMed:15897452). Interacts with BCL2A1 (By similarity). The PHD-type zinc finger mediates the binding to H3K4me3. The N-terminal coiled-coil domain mediates homodimerization. Citrullination by PADI4 within the nuclear localization signal disrupts the interaction with p53 and increases susceptibility to degradation. May be due to a competing donor splice site. Lacks the nuclear localization signal (NLS), resulting in increased cytoplasmic localization. Lacks the nuclear localization signal (NLS), resulting in increased cytoplasmic localization. Lacks the nuclear localization signal (NLS), resulting in increased cytoplasmic localization. Belongs to the ING family.