Tobacco (Nicotiana tabacum L.) and related species had played a pioneer role in the development of plant biotechnology in particular in elaboration of in vitro cultures. There are several types of such cultures, of which the cell suspension cultures in liquid media are considered to be the most important for research approaches and industrial applications. Among the tobacco cell cultures the BY-2 cell system is outstanding and comparable to the HeLa human cell line. It is a unique model cell line for the study of dynamic features of plant cells. Like in the case of Arabidopsis thaliana cells, the BY-2 cell line represents a basic system for investigation of the programmed cell death in plants under influence of various factors. It is also a tool to elucide the biosynthesis of isoprenoids. Among plant cell cultures those of tobacco represent the system which is most frequently utilized for the production of recombinant proteins in which the expression of many therapeutical proteins has been achieved, such as human serum albumin, full and fragment monoclonal antibodies, interleukins, antigens and others.