LRRC4 (Leucine Rich Repeat Containing 4): LRRC4 (Leucine Rich Repeat Containing 4) is a protein predominantly expressed in the brain and involved in neural development. It contributes to the formation and maintenance of the nervous system, as well as neural cell adhesion and signalling. LRRC4 has been researched in connection with brain tumours, particularly gliomas, making it a key area of interest in neurobiology and cancer research.