- Pgp immunochemistry: use with caution: correspondence re: C-H. Kao et al., P-glycoprotein and multidrug resistance-related protein expressions in relation to technetium-99m methoxyisobutylisonitrile scintimammography findings. Cancer Res., 61: 1412-1414, 2001. Cayre, A., Maublant, J., Penault-Llorca, F. Cancer Res. (2002)