MYO1D is an unconventional myosin that functions as an actin-based motor protein with calcium-regulated ATPase activity 1. Its primary role involves endosomal protein trafficking, particularly mediating cargo transfer from early to recycling endosomes, and maintaining planar cell polarity and coordinated ciliary movement in tracheal and brain ependymal cells. MYO1D anchors unphosphorylated EGFR family members at the plasma membrane before their activation by binding to their kinase domains via its C-terminal tail domain 2. It also preferentially binds PDGFRα/β heterodimers and mediates their internalization into early endosomes, thereby regulating downstream ERK1/2 signaling 3. In disease contexts, MYO1D upregulation promotes acute myeloid leukemia progression through SPAG6-mediated translocation to the cell membrane, enhancing EGFR expression and activating PI3K/AKT and ERK signaling 4. MYO1D facilitates colorectal and breast cancer progression by increasing EGFR levels and cell motility 25. Biallelic MYO1D variants (D511N and P765S) are associated with laterality defects, congenital heart disease, and sperm dysfunction in humans, indicating critical developmental roles 67. MYO1D represents both a prognostic biomarker and potential therapeutic target in cancer and developmental disorders.