We believe that the data we have presented concerning the probable influence of specific external magnetic fields on immunological processes and virus replication via the NF-κB and other signaling pathways allows us to put forward a possible role of geomagnetic field fluctuations, and correspondingly, solar activity cycles as factors capable of influencing the occurrence of influenza (and possibly other) epidemics. The gene discussed is NFKB1; the disease is influenza.