The function of PLPP4 (phospholipid phosphatase 4, Ensembl gene identifier ENSG00000203805) is as follows. Magnesium-independent phospholipid phosphatase with broad substrate specificity (PubMed:17590538). Preferentially catalyzes the conversion of diacylglycerol pyrophosphate into phosphatidate but can also act on phosphatidate and lysophosphatidate (PubMed:17590538). Phospholipid phosphatases are involved in both the synthesis of lipids and the degradation or generation of lipid-signaling molecules like diacylglycerol (PubMed:28851360). {ECO:0000269|PubMed:17590538, ECO:0000269|PubMed:28851360}.