On the other hand, SAP-deficient mice fail to activate GC B-cell responses to immunizations with T-dependent antigens, viral infections, and helminth infections (Crotty et al., 2003; Cannons et al., 2006; Kamperschroer et al., 2006; Crotty et al., 2006; McCausland et al., 2007; Moyron-Quiroz et al., 2009; Yusuf et al., 2010; Morra et al., 2005). This evidence concerns the gene SH2D1A and viral infectious disease.