WB using Anti-Cybr antibody shows detection of endogenous Cybr from mouse splenocytes using anti-Cybr antibody to immunoprecipitate and WB (lanes 1-3). Lane 1 shows reactivity of pre-immune sera. Lane 2 shows endogenous Cybr detected with antibody. Lane 3 shows no band detected in lysates prepared from splenocytes of Cybr knock-out mouse. Lane 5 shows direct WB of wt splenocytes. Lane 6 shows direct WB of knock out mouse. Personal Communication, V. Coppola, NCI, Bethesda, MD.