Choline kinase beta (CK), also known as Ethanolamine kinase (EK), Choline kinase-like protein , choline/ethanolamine kinase beta (CKEKB), or Choline/ethanolamine kinase is a protein encoded by the CHKB gene. This gene is found on chromosome 22 in humans. The encoded protein plays a key role in phospholipid biosynthesis. Choline kinase (CK) and ethanolamine kinase (EK) catalyzes the first step in phosphatidylethanolamine biosynthesis. Read-through transcripts are expressed from this locus that include exons from the downstream CPT1B locus.