Lysine demethylase that demethylates both histones and non-histone proteins. Enzymatically inactive by itself, and becomes active following phosphorylation by PKA: forms a complex with ARID5B and mediates demethylation of methylated ARID5B. Demethylation of ARID5B leads to target the PHF2-ARID5B complex to target promoters, where PHF2 mediates demethylation of dimethylated 'Lys-9' of histone H3 (H3K9me2), followed by transcription activation of target genes. The PHF2-ARID5B complex acts as a coactivator of HNF4A in liver. PHF2 is recruited to trimethylated 'Lys-4' of histone H3 (H3K4me3) at rDNA promoters and promotes expression of rDNA. Component of the PHF2-ARID5B complex, at least composed of PHF2 and ARID5B. Interacts with HNF4A and NR1H4. Widely expressed, including in liver. Enzymatically inactive by itself, and become active following phosphorylation by PKA. Belongs to the JHDM1 histone demethylase family. JHDM1D subfamily. Note: This description may include information from UniProtKB.