Table 2 summarizes the quantitative features of the ten genotyping studies (443 cases/1,181 controls) in the meta-analysis that examined associations of the PTPN22 (C1858T) polymorphism with endometriosis. Eight studies from two articles13,16 had Italian subjects (132 cases/528 controls), while one study had Brazilian subjects15 and another had Polish participants,14 with 140 cases/180 controls and 171 cases/310 controls, respectively. The gene discussed is PTPN22; the disease is endometriosis.