Has a key role in phospholipid biosynthesis and may contribute to tumor cell growth. Catalyzes the first step in phosphatidylcholine biosynthesis. Contributes to phosphatidylethanolamine biosynthesis. Phosphorylates choline and ethanolamine. Has higher activity with choline. Belongs to the choline/ethanolamine kinase family. 2 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.