TBC1D10C (also known as EPI64C or carabin) is a dual-specificity GTPase-activating protein with distinct regulatory functions in cellular signaling and immune processes. The protein exhibits GAP activity toward both Rab35 and Ras GTPases, functioning to inactivate these signaling molecules 12. In T cells, TBC1D10C regulates receptor recycling pathways and is essential for immunological synapse formation, where it controls transferrin export and TCR transport to contact sites between T cells and antigen-presenting cells 1. The protein localizes to plasma membrane and intracellular vesicles, with strong recruitment to immunological synapses 1. TBC1D10C has emerged as a significant biomarker across multiple cancers, showing prognostic value in breast cancer, nasopharyngeal carcinoma, clear cell renal cell carcinoma, and melanoma 3456. Its expression correlates with tumor-infiltrating immune cells and immune checkpoint molecules, suggesting roles in tumor immunity and potential as a predictor for immunotherapy response 37. Additionally, TBC1D10C expression is inversely associated with lymphocyte activation and inflammation in both abdominal aortic aneurysm and major depressive disorder, indicating broader immunoregulatory functions beyond cancer 8.