Is it ensure, insure, or assure?
c.1600, from Latin murinus, from mus "mouse" (see mouse (n.)).
murine mu·rine (myur'īn')adj. Of, relating to, or transmitted by a member of the rodent family Muridae, including rats and mice.
Of or relating to a rodent of the family Muridae or subfamily Murinae, including rats and mice.
Caused, transmitted, or affected by such a rodent.