This application requests support for one speaker in the Plenary Symposium and one session-in-depth (SID) at the Congress on Cell and Tissue Culture to be held in Research Triangle Park, N.C., June 4-7, 1994. The Congress, sponsored primarily by the Tissue Culture Association, will include participation by the European scientific community through the European Tissue Culture Association and the European Society for Animal Cell Technology, as well as the Japanese Tissue Culture Association. The theme of the Congress is """"""""Regulation of Cell and Tissue Differentiation"""""""". The Plenary Symposium will focus on cell systems that address the theme and the SID will focus on """"""""Cellular Models of Senescence"""""""".