The IgH Emu enhancer drives late pro-B cell-specific expression of the mouse microRNA followed by the 3'UTR and polyadenylation sequence from the human beta-globin gene. Eight founders were established generating several lines (lines 8 through 15). The pound symbol (#) is used when no line is specified and/or lines are pooled. Northern blot analysis confirmed transcript expression in the spleen. (J:109591)