RAI14 (retinoic acid-induced protein 14) is an actin-binding protein that serves dual roles in normal physiology and cancer biology. In testicular tissue, RAI14 regulates actin dynamics at ectoplasmic specializations to maintain spermatid adhesion and establish sperm polarity, while supporting Sertoli cell tight junction integrity at the blood-testis barrier [UniProt annotation]. Beyond its reproductive function, RAI14 acts as a critical mechanotransducer, responding to mechanical forces from the extracellular matrix by positively regulating YAP activity and interacting with NF2 on filamentous actin 1. This mechanotransduction function links RAI14 to Hippo pathway signaling, a key regulator of cell proliferation and organ size. Clinically, RAI14 dysregulation is significantly associated with cancer progression across multiple tumor types including gastric, colorectal, breast, and head and neck cancers 234. RAI14 promotes tumorigenesis through multiple pathways including AKT/mTOR signaling, YAP/Hippo signaling, EMT promotion, and apoptosis inhibition 2. In gastric cancer, RAI14 is upregulated through the circNFATC3/miR-23b-3p regulatory axis and correlates with poor overall and progression-free survival 56. High RAI14 expression predicts chemotherapy resistance and poor prognosis in APC-mutant colorectal cancer 4. Additionally, RAI14 facilitates immune evasion by promoting lysosomal degradation in macrophages, thereby suppressing antigen presentation in hepatocellular carcinoma 7. These findings support RAI14's translational potential as a diagnostic/prognostic biomarker and therapeutic target across multiple cancer types.