Rather, the higher efficiency of the CD103+ RDC subset to cross-present particulate viral antigen vaccine or (as recently reported) soluble proteins introduced into the respiratory tract [22] as well as viral antigen produced during natural infection most likely reflects elevated expression of components of the class I presentation pathway selectively by CD103+ RDC and/or unique adaptation of this RDC subset for the uptake, processing and delivery of processed antigen to MHC class I molecules [49], [50] (T. Kim and T. Braciale, Manuscript in preparation). This evidence concerns the gene ITGAE and infection.