MAPKAP1 (MAPK-associated protein 1), also known as SIN1, is a core scaffolding component of mTOR complex 2 (mTORC2), though isoform 4 does not participate in this complex 1. As a major mTORC2 partner, MAPKAP1 acts as a scaffold protein responsible for substrate specificity of the mTOR catalytic subunit and mediates AKT phosphorylation at S473 2. This function is critical for integrating growth factor signals and regulating cellular proliferation and metabolism. MAPKAP1 participates in multiple oncogenic pathways beyond mTORC2, including connections with Hippo, WNT, Notch, and MAPK signaling 1. Functionally, MAPKAP1 overexpression promotes cancer cell proliferation, invasion, and metastasis, while its inhibition decreases tumor growth in vitro and in vivo 1. The protein also regulates epithelial-mesenchymal transition, stress response, and lipogenesis 1. Recent genomic studies identified MAPKAP1 as a novel genetic risk locus associated with chr9 dry cough and ACEi-induced cough, implicating neurological dysfunction in cough hypersensitivity 3. Given its central role in mTORC2-mediated tumorigenesis and diverse cellular processes, MAPKAP1 represents a promising therapeutic target for cancer treatment with potential advantages over direct mTOR inhibitors.