PHKB gene encodes phosphorylase kinase subunit beta involved in glycan biosynthesis and glycogen metabolism. PHKB activity is regulated by phosphorylation of various serine residues, and catalyzes the phosphorylation of serine in certain substrates, including troponin I. Phosphorylase kinase (PhK) complex, composed of alpha, beta, gamma, and delta subunits, stimulates energy production from glycogen in the cascade activation of glycogenolysis. Its large homologous alpha and beta subunits regulate the activity of the catalytic gamma subunit.