Levels of total cellular CD86 measured by Western blot for select variants.A, CD86 and GAPDH levels were measured by western blot from HeLa whole cell lysates expressing the indicated CD86 variants in the absence (−DOX) or presence (+DOX) of MARCH1. Three separate experimental blots from (A) were quantitated by densitometry, and GAPDH-normalized CD86 signals (mean ± standard deviation) from three separate experiments are shown (B and D). DOX, doxycycline; MARCH1, membrane-associated RING-CH 1; MIR2, modulator of immune recognition 2.