PIKfyve, also known as phosphatidylinositol 3-phosphate 5-kinase, is the sole member of its family, responsible for generating phosphatidylinositol (PI) into PI(3,5)P2. It comprises a C-terminal catalytic domain and multiple N-terminal regulatory domains, predominantly localized to membrane systems such as early endosomes and the Golgi apparatus. PIKfyve regulates endocytosis, vesicular transport, membrane fluidity, and ion channel function, serving as a crucial regulator of intracellular signaling and membrane trafficking. It is expressed in various cell types and tissues, and abnormalities in its activity and expression levels are associated with neurodegenerative diseases, muscular atrophy, and cancer. Specific gene mutations affecting PIKfyve function may disrupt cellular homeostasis and contribute to disease development.