The major pathway for the biosynthesis of phosphatidylcholine occurs via the CDP-choline pathway. Choline kinase, the initial enzyme in the sequence, plays a role in cell growth proliferation. A related protein, ChoKB (also, known as choline kinase beta), is a 395 amino acid enzyme that catalyzes the phosphorylation of choline by ATP in the presence of magnesium, thereby yielding phosphocholine and ADP. Like all choline kinases, ChoKB possesses ethanoalamine kinase activity and catalyzes the phosphorylation of ethanolamine. The gene encoding ChoKB is located less than 1 kb upstream of the CPT1B gene, suggesting that the ChoKB gene may regulate transcription CPT1B. In mice, mutations and/or deletions in the gene encoding ChoKB are the cause of hindlimb muscular dystrophy and neonatal bone deformity.