Human primary CD14-positive monocytes, isolated from healthy donors and differentiated into macrophages after 6 days of exposure to M-CSF, were infected by KSHV, as previously described.3 After 24 h, viral infection was demonstrated by detecting the expression of the KSHV early lytic antigen K-bZIP by western blot (Fig. 1a) and by IFA (Fig. 1b) and by qRT-PCR assessing the expression of latent, early lytic and late lytic antigens, LANA, ORF50 and K8.1, respectively (Fig. 1c). The gene discussed is CSF1; the disease is viral infectious disease.