Individual genes such as CD27, CD40, TIRC7, cytokines (interferon-γ, interleukin [IL]-2, IL-4, IL-6, IL-8), and cytotoxic T-cell effector molecules (Perforin, Granzyme B, FasL) have been previously found to be elevated in rejecting biopsy samples [24]–[30] and peripheral in blood [31]–[33] at the time of cardiac allograft rejection, but many of these are also regulated during infection and other causes of inflammation. Here, GZMB is linked to infection.