The function of Ensembl gene identifier ENSG00000180817 (PPA1, inorganic pyrophosphatase 1) is as follows. Catalyzes the hydrolysis of inorganic diphosphate into two phosphate molecules (PubMed:33036755, PubMed:38428647). Has MAP kinase serine/threonine phosphatase activity toward c-Jun N-terminal kinase (JNK) and, in neuronal cells, is involved in the negative regulation of neurite growth via JNK dephosphorylation (By similarity). {ECO:0000250|UniProtKB:Q9D819, ECO:0000269|PubMed:33036755, ECO:0000269|PubMed:38428647}.