The polyomaviruses are widely distributed in nature, and the human population is threatened by three different viruses: the BK virus (BKV), the JC virus (JCV), and the simian virus (SV40), which was first recognized in the context of the polio vaccine in the late 1950s. These viruses can cause various health problems, but in many cases, the infection remains hidden without causing serious symptoms. Infection with polyomaviruses can occur early in childhood, and according to epidemiological data, virtually everyone has encountered these viruses by adulthood. JCV was first isolated in 1971, while the discovery of BKV also occurred around this time. The viruses generally enter the body through the respiratory…