NOS3 and stroke disorder: In addition, Egger asymmetry tests and funnel plots showed no substantial evidence of publication bias in the nine meta-analyses for which four or more studies had been published (apolipoprotein E ε4, and ε2; SERPINA3 A/T; eNOS T786C; ACE/ID; MTHFR C677T; factor XIII Val/Leu and SERPINE1 4G/5G), although it is acknowledged that at times the study numbers for each gene were small as was the number of subjects for each study making the point estimates less reliable when compared against our previous larger meta-analyses in stroke [5], [6].