To investigate this in the context of viral infection (in stably infected HuARLT2-rKSHV cells after lytic induction), an immunofluorescence assay (IFA) was performed using monoclonal antibodies to K1 [65] and K15 [49]; examples of cells expressing K15 (shown in green) alone or together with K1 (shown in red) are shown in Fig 4A. The gene discussed is KRT1; the disease is viral infectious disease.