Phosphatidylinositols, comprising about 10% of total cellular phospholipids, are glycerophospholipids featuring a glycerol backbone, two non-polar fatty acid tails (primarily C16:0 and C18:0), and a polar inositol head group. Synthesized from cytidine diphosphate diacylglycerol (CPD-DAG) and myoinositol via phosphoinositol synthase, these compounds play pivotal roles in cellular processes, including calcium regulation, vesicle trafficking, mitogenesis, cell survival, and actin rearrangement. Phosphorylation of their inositol rings produces phosphoinositides, crucial for these cellular functions. [Matreya, LLC. Catalog No. 1048]