An increase in CTLA-4 mRNA expression was observed in PBMCs infected with BVDV alone, but not the cells treated with FTA alone or BVDV plus FTA compared to the controls at 48 and 72 h after infection (P = 0.0002 and P < 0.0001, respectively; Fig 3A). The gene discussed is CTLA4; the disease is infection.