Jβ usage of Vβ13 or Vβ6 in control infants. Both Vβ6 and Vβ13 generally used a variety of 13 Jβ genes with a bias for Jβ2; the average Jβ1:Jβ2 ratios as a whole were 42:58 for Vβ6 and 33:67 for Vβ13. There was no Jβ gene usage greater than 20%.