Cbr1 +/- mouse hearts are protected from doxorubicin-induced injury. Top, the organized pattern of myofiber striations with central nuclei, as expected in untreated mice, are observed in doxorubicin-treated Cbr1 +/- mice. Bottom, doxorubicin treatment, in contrast, produced necrosis (open arrow) and mineralization (filled arrow) in wild-type mice. Sections were stained with hematoxylin and eosin. For details, see the article by Olson et al. on p. 6602 of this issue.