The mixed lineage kinase (MLK) family is a group of serine/threonine kinases in the MAPK signaling pathway, including members such as MLK1, MLK2, and MLK3. They consist of a kinase domain, an SH3 domain, and a Cdc42/Rac interactive binding domain, primarily located in the cytoplasm. The MLK family plays a crucial role in regulating cell stress response, apoptosis, and neuronal signal transduction. By activating the JNK and p38 MAPK signaling pathways, they influence cell stress response and survival. The expression of the MLK family is specific in different tissues and cells, and mutations or dysregulation in their gene expression are associated with various diseases, including neurodegenerative diseases, cancer, and inflammatory disorders.