Tamoxifen injections in αMHC-MerCreMer mice induce a loxP-independent DNA damage response, leading to myocardial dysfunction and death. Tamoxifen injections in αMHC-MerCreMer mice induce a loxP-independent DNA damage response, leading to myocardial dysfunction and death. The proposed sequential model of molecular, cellular and tissue mechanisms is provided in the flow diagram. The measured parameters indicating involvement of the proposed mechanisms are indicated in smaller italicized font. Kevin Bersell et al. Dis. Model. Mech. 2013;6:1459-1469 © 2013. Published by The Company of Biologists Ltd