- Beta1 integrin is not essential for hematopoiesis but is necessary for the T cell-dependent IgM antibody response. Brakebusch, C., Fillatreau, S., Potocnik, A.J., Bungartz, G., Wilhelm, P., Svensson, M., Kearney, P., Körner, H., Gray, D., Fässler, R. Immunity (2002)