AbstractThe composition of a series of critical summaries is necessarily idiosyncratic, but in this compliation I have been guided by the recent publication of reviews and monographs on the subject.1–3 consequently, it seems reasonable to focus on more fundamental areas of research which may lie outside the normal reading of most pathologists. Nevertheless, I regard these burgeoning areas as being likely to impinge on our research, if not our practice, in the near future. I will concentrate on four areas that I consider of particular interest. First, regulation of the cell cycle; second, arrest of proliferation; third, programmed cell death; and finally, the generation of novel markets of prolkiferation.