Strain specific ITGA4 expression analysis in WT and heterozygous B-hITGA4 mice by flow cytometry.  Splenocytes were collected from C57BL/6(+/+) and heterozygous B-hITGA4 (H/+) mice. Mouse ITGA4 was detectable both in C57BL/6(+/+) mice and heterozygous B-hITGA4 mice. Human ITGA4 was detectable in heterozygous B-hITGA4(H/+) mice but not C57BL/6(+/+) mice .