To validate the viral ORF clone collection built using ViralORFeome pipeline, we tested a subset of 66 ORFs (Figure 3a ORFs were expressed in fusion downstream of the red fluorescent protein Cherry and constructs transfected in human cells to achieve subcellular localization (Figure 3b ). We observed a specific localization pattern distinct from Cherry alone for most constructs, demonstrating that viral ORFs are properly expressed in this system. In addition, and even if the N-terminal tag was expected to alter the localization of proteins like viral envelopes, observed localization patterns were generally consistent with literature. For example, expression of nsP1 not only from Semliki Forest virus and Sindbis virus (25) but also Chikungunya virus induced characteristic filopodia-like extensions in transfected cells. The capsid of yellow fever virus (C) was found in the nucleus where it accumulated in a dot-like pattern, reminiscent of nucleoli, as reported for C of dengue and Japanese encephalitis viruses (26, 27) .