However the PGK1-normalized BZLF1 transcript level at day 5 post-infection was 300-fold less than that of productively-infected Akata-BL cells; at present we cannot distinguish whether these signals are derived from a very small number of infected cells undergoing spontaneous reactivation or a general low level of BZLF1 transcription in all the culture. This evidence concerns the gene PGK1 and infection.