With great sadness and regret, we inform about the death of Dr. Jan Czarnecki, who died on May 29, 2017 in Jelenia Góra, the eminent Polish chemist and biotechnologist, the creator of the Polish thymus hormone preparation and the technology of producing highly purified lysozyme dimer, member of an international group of specialists and researchers who in 1994 led to the registration of Lydium-KLP.