CD8A and infection: However, upon infection, we observed a significant bias toward higher TCR2+ frequency in the CD8+ T cells of line 6 birds in replicate 2, beginning on day 8 (p < 0.05); and in replicate 1, this bias was observed across both lines (p < 0.001), but only day 21 in line 6 was individually statistically significant (p = 0.002) (Figure 2C).