Based on limited published evidence, PRRG3 (proline rich and Gla domain 3) is an X-linked gene with predicted involvement in blood coagulation and proteolysis based on GO annotations indicating serine-type endopeptidase activity and membrane localization. PRRG3 was identified as a candidate gene in the MYP1 locus region (Xq28) associated with X-linked nonsyndromic high myopia, though sequencing did not reveal causative mutations 1. Additionally, PRRG3 was identified as one of 14 genes in a multigene signature predictive of metastatic outcome in triple-negative breast cancer 2. However, specific molecular function and tissue-specific roles remain largely uncharacterized.