Merkel cell carcinoma (MCC) is a rare aggressive neuroendocrine skin cancer of elderly patients. Generally, it originates from Merkel cells of the basal layer of the epidermis characterized by typical neuroendocrine granules (neuron-specific enolase; NSE+) and keratin filament (cytokeratin-20; CK20). Its incidence has been increasing in the last two decades, likely because of improved ability t...

To the Editor: The human polyomaviruses JC and BK are known to cause persisting infections, which are usually asymptomatic in immunocompetent patients but may lead to severe disease in those who are immunosuppressed (1). Recently, 2 novel viruses of the family Polyomaviridae were detected in respiratory samples and named KI (2) and WU polyomavirus (WUPyV) (3). To investigate the frequency of WU...

The polyomavirus JC virus (JCV) is a small nonenveloped DNA virus that asymptomatically infects about 80% of healthy adults and establishes latency in the kidney tissue. In case of immunodeficient hosts, JCV can lytically infect the oligodendrocytes, causing a fatal demyelinating disease, known as Progressive Multifocal Leukoencephalopathy (PML). Although the reactivation of another human polyo...

23 24 Hundreds of virus-encoded microRNAs (miRNAs) have been uncovered, but an 25 in depth functional understanding is lacking for most. A major challenge for 26 the field is separating those miRNA targets that are biologically relevant from 27 those that are not advantageous to the virus. Here we show that miRNAs from 28 related variants of SV40 polyomavirus have differing host target repertoi...

•Structural mimicry of host proteins is a pervasive strategy across earth’s virome•Majority the >6,000,000 cataloged mimics cannot be discerned through sequence•Protein structure space utilized by viruses dictated proteomes•Knowledge viral provides clues about pathophysiology COVID-19 Viruses deploy genetically encoded strategies to coopt machinery and support replicative cycles. Here, we use p...