The tetracycline-responsive element drives the expression of murine H2-K1b. Crossing mice bearing this transgene with mice that express the tetracycline transactivator (tTA) or reverse transactivator (rtTA) protein under the control of a tissue-specific promoter permits regulation by tetracycline (or one of its derivatives) withdrawal/administration of the expression of H2-K1 in the progeny. The pound symbol (#) is used when line is not specified and/or lines are pooled.