EFNA1 and infection: The most highly up-regulated genes were the interleukin-18 binding protein at the first week of the third Immunising infection (IL18BP, 1/6 comparisons; 1.62-fold in PI_I3) and ephrin-A1 (EFNA1, 2/6 comparisons; 1.56-fold in PI_I3, Additional file 1).