After infection (D7), CD9+ subset was significantly increased (compared with D0) in both iLN and GT, of note suppressive pDC (Siglec-H+) was under detective level in GT post infection, suggest that host response to invading pathogens with increased pro-inflammatory pDC, further initiate protective immunity; also with decrease suppressive pDC, which unlikely to benefit host fight against infection. The gene discussed is CD9; the disease is infection.