Furthermore, in our study, a decrease in the mRNA expression of PLPP3 in breast tumors was found to be associated with the promoter hypermethylation, whereas no considerable change in the promoter methylation was observed for SGPP1. Decreased expression of S1P-catabolizing enzymes in tumors may lead to elevated levels of S1P in tumor tissues. Here, PLPP3 is linked to neoplasm.