BAX and viral myocarditis: In addition, no apoptosis was detected in the hearts of KO mice with acute viral myocarditis: no TUNEL positive cells were detected, and the mRNA levels of Bax, Bcl-2, and cyclinD1 were not significantly different from those in the hearts of WT mice on Day 5 post-infection (Supplemental Data Figure S1, TUNEL stain and RT-PCR).