The same may apply to PPARG rs1801282, which had been extensively studied in the past (before the GWA investigations) in many other studies, again with clear association in the summary effect, but with some co-existing between-study heterogeneity [23]. Efforts to identify the true functional culprit variants of PPARG (if different from rs1801282) are ongoing. By comparison, the other two variants that been already known and extensively studied before the 3 GWA investigations (KCNJ11 rs5215 and TCF7L2 rs7901695) have I2 = 0 in both the main and sensitivity meta-analyses.
