ARMH3 or Armadillo Like Helical Domain Containing 3, also known as UPF0668 and c10orf76, is a protein that in humans is encoded by the ARMH3 gene. Its function is not currently known, but experimental evidence has suggested that it may be involved in transcriptional regulation. The protein contains a conserved proline-rich motif, suggesting that it may participate in protein-protein interactions via an SH3-binding domain, although no such interactions have been experimentally verified. The well-conserved gene appears to have emerged in Fungi approximately 1.2 billion years ago. The locus is alternatively spliced and predicted to yield five protein variants, three of which contain a protein domain of unknown function, DUF1741.