PTGS2 and major depressive disorder: In the case of linked genotypes of g.70677994G>A (rs2166975)—TGFA and g.186643058A>G (rs5275)—PTGS2, we found that link between A/G-G/G of this genes was associated with higher risk of appearance of the MDD, while G/G-G/G as well as A/A-G/G genotypes decreased this chance.