- Improved post-transcriptional processing of an MDR1 retrovirus elevates expression of multidrug resistance in primary human hematopoietic cells. Knipper, R., Kuehlcke, K., Schiedlmeier, B., Hildinger, M., Lindemann, C., Schilz, A.J., Fauser, A.A., Fruehauf, S., Zeller, W.J., Ostertag, W., Eckert, H.G., Baum, C. Gene Ther. (2001)