Functions as a transcriptional regulator. Functions in cell cycle regulation through CCNA2. Plays an important role in chromosome condensation during the meiotic G2/M transition of spermatocytes. Plays a role in postnatal myogenesis, is involved in satellite cell activation (By similarity). Positively regulates IGF2 expression through PLAG1 and in a PLAG1-independent manner (PubMed:28796236). {ECO:0000250|UniProtKB:P52927, ECO:0000269|PubMed:14645522, ECO:0000269|PubMed:28796236}. This is the function of HMGA2 (high mobility group AT-hook 2, Ensembl gene identifier ENSG00000149948).