Although antiretroviral therapy does not eradicate latent HIV that resides in resting T cells, efforts are underway to determine how this latent HIV can be awakened. However, Ho et al. showed that the latent reservoir might be much larger — up to 60-fold — than previously estimated. The authors analysed non-induced proviral clones from patients treated with antiviral therapy and showed that over 10% had intact genomes and were capable of being transcriptionally active. The authors note this means that these viruses might become active in vivo, thus increasing the barrier that needs to be overcome to cure HIV.