ARMC3 contains 12 ARM repeats. ARM (Armadillo/beta-catenin-like) domains are imperfect 45-amino acid repeats involved in protein-protein interactions. ARM domain-containing proteins, such as ARMC3, function in signal transduction, development, cell adhesion and mobility, and tumor initiation and metastasis. The specific function of ARMC3 is not yet known.Isoform 2 is expressed in skeletal muscle, brain, lung, kidney, prostate and testis. Isoform 3 is mainly expressed in skeletal muscle, liver, spleen and thymus. Expressed in many cancer tissues and cell lines.