Panel 51. It took more than 25 years between the discovery of HCV (in the early 1990s) and its visualization by electron microscopy by negative staining, by young researchers from my team, in 2016. Several reasons explain this very long wait. Initially, this virus could only be discovered thanks to molecular biology techniques. Its RNA genome was therefore known well before its proteins and biological characteristics. It was not until 2005 that the first cellular systems were available to cultivate the virus in the laboratory. Moreover, this virus proved to be fragile with a tendency to degrade when attempts were made to purify it. Finally, its curious association with apolipoproteins meant that it was long confused with lipoproteins circulating in the blood.