Collaborations are traditionally strong with Assoc. Prof. M. Stiborová´s laboratory at Charles University (Dr. Stiborová, Dr. Hudeček) and with Dr. P. Souček´s lab at the Natl. Institute of Public Health, Prague, and with lab of immunopharmacology headed by Dr. Zídek at the Institute of Experimental Medicine, Academy of Sciences, Prague. International collaborations and contacts include in Europe lab of Dr. Reinhard Lange (INSERM and University of Montpellier, France), laboratory of Prof. Peter Hildebrandt (Max Vollmer Institute, TU Berlin), laboratory of Prof. Damjana Rozman (University of Ljubljana, Slovenia), in the U.S.A. lab of Prof. F.P. Guengerich (Vanderbilt University, Ctr in Mol. Toxicology, Nashville, TN).