CD79A and nasopharyngeal carcinoma: Subsequently, in the 1980s, serum levels of Epstein–Barr capsid antigen (VCA) immunoglobulin A (IgA) were established as one of the indicators for screening patients for NPC21 and the expression of latent genes in EBV-infected states was also discovered.22 With the use of qPCR to detect cell-free EBV DNA in 1999, a relationship between an increased risk of NPC due to EBV infection and poor prognosis was established.23 Since then, EBV DNA has become the gold standard for biological markers of NPC.