The four projects in the SCOR will be interlined through the Mouse Core. The functions of the mouse core will be to (1) create transgenic mouse be oocyte injection of various expression vectors, (2) generate mutant mice by homologous recombination and blastocysts injection of modifier embryonic stem(es) cell, (3) set up inc intercrosses between various mutants and transgenic mouse strains, (4) provide advice and technical expertise to members of the four laboratories on mouse techniques, and (5) to maintain breeding colonies of the large number of transgenic and knockout mouse that can be provided to each laboratory as needed. Mice for the Core will be housed at Southwestern and UCSD and will be readily exchanged as needed.