“…So-called “resistant” White Leghorn lines 15I (herein referred to as 15), 7 2 , C, EB and O displayed no mortality, whereas mortality rates for White Leghorn lines N, 6 1 and W were 6.5%, 8.3% and 24.4%, respectively, and the mortality rates for Rhode Island Red, Light Sussex and Brown Leghorn breeds were 22.2%, 40.7%, and 79.2%, respectively [ 6 , 7 ]. To identify gene targets that could be exploited to engineer IBD resistant chickens, several groups have conducted transcriptional profiling of the BF of the lines following IBDV infection, either by microarray [ 8 , 9 ] or by RNA-sequencing (RNA-seq) [ 10 , 11 ]. Two studies [ 8 , 9 ] compared White Leghorn line 6 1 (8.3% mortality) with Brown Leghorn chickens (79.2% mortality) and their results indicated that an early, rapid, pro-inflammatory response and more extensive activation of apoptosis was evident in the more resistant line, suggesting that these responses may limit viral replication and pathology [ 8 ].…”