PPP1R16B encodes a regulatory subunit of protein phosphatase 1 (PP1) that serves multiple cellular functions, particularly in vascular biology and cellular signaling. The protein acts as a positive regulator of pulmonary endothelial cell barrier function and is involved in PI3K/AKT signaling pathway regulation, angiogenesis, and endothelial cell proliferation 1. PPP1R16B facilitates PKA-mediated moesin dephosphorylation, which is crucial for endothelial barrier protection against thrombin stimulation 2. The protein promotes interaction between PPP1CA and RPSA/LAMR1, facilitating RPSA/LAMR1 dephosphorylation 3, and is involved in EEF1A1 dephosphorylation 4. Disease relevance includes associations with colonic diverticulosis through genetic variants affecting extracellular matrix remodeling 5, and hypermethylation patterns linked to secondary progressive multiple sclerosis prognosis 6. The gene shows differential methylation patterns associated with early childhood obesity risk 7 and is involved in irritable bowel syndrome with diarrhea through microRNA regulatory networks 8. PPP1R16B expression changes are also observed in tuberculosis and rheumatoid arthritis, suggesting roles in immune-related pathways 9.