“…Control rodent survival at 24 mo during the 1980s and 1990s has become highly variable Hart et al, 1995;Haseman & Rao, 1992;Keenan et al, 1992Keenan et al, , 1994aKeenan et al, , 1994bKeenan et al, , 1995aKeenan et al, , 1995bKeenan et al, , 1996Keenan et al, , 1997Lang, 1991;Laroque et al, 1997;Rao et al, 1990;Roe, 1994;Turturro et al, 1995Turturro et al, , 1996. For example, male Sprague-Dawley rat survival ranged from 7 to 73%, male Fischer 344 rats from 36 to 85%, male CD-I mice from 20 to 80%, and male B6C3F1 mice from 40 to 97% Haseman & Rao 1992;Keenan et al, 1994b;Lang, 1991;Rao et al, 1990;Turturro et al, 1995Turturro et al, , 1996.…”