MICER vectors MHPN235b18 (16:96327324-16:96331804 Mb) located between B3galt5 and Igsf5 and MHPN352i16 (16:97977263-16:97982380 Mb) were used to insert loxP sites proximal to Igsf5 and distal to Zbtb21. Cre-mediated recombination duplicated the sequence floxed by loxP sites. (J:227899)