Although a larger number of B cells (approximately 8% of cells) were infected with the revertant (WT) virus in comparison to the Zp-V3 mutant virus (approximately 3% of cells), the level of Z expression assessed by immunoblot on day 3 after infection was greater in the Zp-V3 mutant infected cells (Fig 7B). The gene discussed is HEPHL1; the disease is infection.