In IBV-infected H1299 cells, significant induction of Mcl-1 (1.67–9.51 fold) was detected from 12–24 hours post-infection; however, relatively less efficient induction of Bak (1.09–2.83 fold) was observed as the basal level of Bak is much higher in this cell line. The gene discussed is BAK1; the disease is infection.