Based on limited published evidence, PCDHGC5 is a calcium-dependent cell-adhesion protein potentially involved in establishing and maintaining neuronal connections through synapse organization and cell adhesion molecule binding. UniProt annotations indicate localization to the plasma membrane. Beyond its canonical neuronal function, PCDHGC5 has been identified as a tumor-associated antigen in alveolar rhabdomyosarcoma (ARMS), showing overexpression in tumor tissues 1. Low anti-PCDHGC5 autoantibody levels independently predicted worse event-free survival in ARMS patients 1. Additionally, PCDHGC5 promoter methylation was detected in pancreatic ductal adenocarcinoma 2, suggesting potential epigenetic dysregulation in cancer.