Required to suppress inappropriate homologous recombination, thereby playing a central role DNA repair and in the maintenance of genomic stability. Antagonizes homologous recombination by interfering with the formation of the RAD51-DNA homologous recombination structure. Positively regulate the poly(ADP-ribosyl)ation activity of PARP1; however such function may be indirect (By similarity). Binds single-strand DNA and poly(A) homopolymers. Interacts with RAD51 and PCNA. Interacts with PARP1 (By similarity). Interacts with TASOR (By similarity). Localizes to chromatin in response to S phase arrest but not in mitosis. Targeted to chromatin via its interaction with PCNA (By similarity). Present in testis (at protein level). Expressed in testis, gastrointestinal tract (jejunum, ileum, and colon) and immune system (thymus and spleen). Weakly expressed in lung, kidney, pituitary gland and muscle. The gene encoding Arom is located in the opposite strand of the gene encoding MCH. Belongs to the PARI family.