TNFSF15 and thymus atrophy: PVM-infected mice showed increased relative levels of TL1A and IL-18 during acute thymus atrophy at Days 10 and 14 (Fig. 7I–J), while MCVM-infected mice displayed increased TL1A and IL-18 only during acute thymus atrophy on Day 5, but not during the early infection stage (Day 2), or in the recovery phase (Day 8) (Fig. 7K–L).