GIPC1 (GIPC PDZ domain containing family member 1) is a scaffolding protein that functions primarily in protein-protein interactions and cellular signaling through its PDZ domain. GIPC1 serves as an adaptor protein that facilitates various signaling pathways, including TGFβ signaling by enhancing TGFβ type III receptor expression at the cell surface 1. The protein also functions as a scaffold linking neuropilin-1 (NRP1) and TrkA receptors to myosin VI in nociceptors, where it plays a crucial role in nerve growth factor (NGF) signaling and pain transmission 2. Additionally, GIPC1 acts as both a protein interaction partner and transcription factor for MACC1, regulating metastasis-associated pathways in colorectal cancer 3. The gene is associated with oculopharyngodistal myopathy 2 (OPDM2), caused by CGG repeat expansions in GIPC1's 5' UTR region that lead to production of toxic poly-glycine proteins through repeat-associated non-AUG translation 45. These poly-glycine aggregates sequester autophagy receptors and disrupt autophagic flux, contributing to neurodegeneration 5. GIPC1 expression is frequently downregulated in various tumors including kidney, colorectal, gastric, and prostate cancers, potentially disrupting TGFβ signaling 1. In breast cancer, high GIPC1 expression combined with CAPG predicts bone metastasis development and treatment response to bisphosphonates 6.