International Review of Cytology presents current advances and comprehensive reviews in cell biology both plant and animal. Authored by some of the foremost scientists in the field, each volume provides up-to-date information and directions for future research. Articles in this volume address endocrine disruption in invertebrates, the biology of lysenin, testican-1, transgenic mice as in vivo models of lymphomagenesis, bacterial endocytobionts of ciliophora, and Basic helix-loop-helix proteins expressed during early embryonic organogenesis.