HCCS and graft versus host disease: In murine GvHD models involving Mls-disparate mouse strains, GvHD has been shown to be associated with expansion of donor-type T cells bearing TCR Vβ chains that are specific for host-type Mls antigens (Sefrioui et al. 2000; Johnson et al. 1995; Billiau et al. 2002).