No begomoviruses lacking C4/AC4 have been described until now, however, other genera within the Geminiviridae: Becurtovirus, Capulavirus, Grablovirus, Eragrovirus, Mastrevirus and other species also lack C4, showing that in these viruses C4 is not essential for viral infection and function may be compensated by other viral proteins. This evidence concerns the gene C4A and viral infectious disease.