EPS8L3 (EPS8 signaling adaptor L3) is a member of the EPS8 family that functions as a signaling adaptor protein involved in actin cytoskeleton regulation and cellular growth control. The protein exhibits guanyl-nucleotide exchange factor activity and actin binding capabilities, localizing to cytoplasm, plasma membrane, and membrane ruffles 1. EPS8L3 promotes cellular proliferation through multiple mechanisms: it modulates EGFR dimerization and internalization, affecting EGFR-ERK pathway activation 2, and hyperactivates AKT signaling while inhibiting FOXO1 transcriptional activity 3. In hepatocellular carcinoma, EPS8L3 is overexpressed and associated with poor prognosis, promoting both proliferation and metastasis by downregulating p21/p27 and upregulating matrix metalloproteinase-2 24. The protein also regulates cancer stem cell markers CD24, CD13, and EpCAM through SP1-mediated transcriptional control 5. Disease-wise, EPS8L3 mutations cause Marie Unna hereditary hypotrichosis (MUHH), an autosomal dominant hair disorder characterized by coarse, wiry hair and progressive hair loss 16. This dual role in hair follicle development and cancer progression highlights EPS8L3's importance in both normal cellular function and pathological states.