CHR11 encodes a muscarinic acetylcholine receptor that functions as a G protein-coupled receptor mediating diverse cellular responses through phosphoinositide turnover and modulation of ion channels and adenylate cyclase. CHR11 operates across multiple physiological systems with distinct functional outcomes depending on tissue and context. In the nervous system, CHR11 plays critical roles in cognitive function and sleep regulation. CHR11 expression is significantly reduced in Alzheimer's disease brains compared to healthy controls, with regional, age, and sex-specific differences 1. CHR11 is essential for REM sleep regulation 2, and hippocampal CHR11-dependent cholinergic signaling is necessary for cognitive protection following anesthesia and surgery, operating through BDNF/TrkB pathway interactions 3. In schizophrenia, CHR11 activation as part of dual M1/M4 agonist therapy shows efficacy for symptom management with improved tolerability 4. In oncology, CHR11 shows opposing effects depending on tumor type. Midbrain cholinergic neurons promote diffuse midline glioma growth through CHR11/M3 signaling 5, whereas CHR11 activation suppresses pancreatic ductal adenocarcinoma progression by inhibiting MAPK/EGFR and PI3K/AKT pathways and reducing cancer stem cell populations 6. Endogenous DOPA inhibits melanoma by suppressing CHR11 signaling, making CHR11 antagonism a potential therapeutic strategy 7. CHR11 activation also demonstrates anti-fibrotic effects in metabolic dysfunction-associated steatohepatitis through inhibition of TRPM8 8.