PLD1 also known as PC-PLD1 is a phosphatidylcholine-specific phospholipase which catalyzes the hydrolysis of phosphatidylcholine in order to yield phosphatidic acid and choline. PLD1 plays a crucial role in cellular signaling and membrane dynamics, as PLD1 is involved in the hydrolysis of phosphatidylcholine to produce phosphatidic acid, a key lipid mediator that influences various cellular processes, including cell growth, migration, and differentiation. PLD1 is primarily localized to secretory granules, where PLD1 participates in the regulation of macrophage phagocytosis and is activated by G protein-coupled and receptor tyrosine kinase signaling pathways. Notably, PLD1′s activity is essential for the stimulation of downstream signaling events, such as ERK phosphorylation and IL-8 secretion in bronchial epithelial cells, highlighting PLD1′s importance in inflammatory responses.