> # down regulation of peroxidase genes
> #
> contingency.table;
             differential
Group         down5pct NOT: down5pct
  peroxidases       35            41
  all genes       3338         17800

> ft<-fisher.test(contingency.table);
> ft;  # odds ratio <1: under-represented; >1: over-represented

	Fisher's Exact Test for Count Data

data:  contingency.table 
p-value = 5.842e-10
alternative hypothesis: true odds ratio is not equal to 1 
95 percent confidence interval:
 2.809802 7.336726 
sample estimates:
odds ratio 
  4.551863 


> # strong down regulation of peroxidase genes
> #
> contingency.table;
             differential
Group         down5pct, strong NOT: down5pct, strong
  peroxidases               14                    62
  all genes                100                 21038

> ft<-fisher.test(contingency.table);
> ft;  # odds ratio <1: under-represented; >1: over-represented

	Fisher's Exact Test for Count Data

data:  contingency.table 
p-value < 2.2e-16
alternative hypothesis: true odds ratio is not equal to 1 
95 percent confidence interval:
 23.72352 89.27042 
sample estimates:
odds ratio 
  47.45978