The MARK family includes four known kinases: MARK1, MARK2, MARK3, and MARK4, all featuring a conserved kinase domain and regulatory regions. They are localized in various cell types and tissues, primarily involved in regulating microtubule stability and cell polarity. MARK kinases influence signaling and intracellular transport by phosphorylating microtubule-associated proteins and other substrates. Gene expression varies across tissues, and specific mutations are associated with neurodegenerative diseases and cancer.