SMIM23 or Small Integral Membrane Protein 23 is a protein which in humans is encoded by the SMIM23 or c5orf50 gene. The longer mRNAisoform is 519 nucleotides which translates to 172 amino acids of a protein.[1] In recent advancements, researchers have identified this gene, along with a few others, could potentially play a role in how facial morphology arises in humans.[2]