Not content to rest on their laurels, Pääbo and Zeberg have just kicked things up a notch. The pair recently reported on the bioRxiv preprint server that another exclusively Neandertal variant, this time in the promoter region of the DPP4 gene at chr2q24.2, is really pulling the strings on COVID susceptibility. DPP4 is a widely expressed extracellular dipeptidyl peptidase involved in immune function and glucose metabolism. As it happens, DPP4 is also the receptor gene for the MERS coronavirus. Now we are getting somewhere.
Although other researchers have insisted DPP4 is not a SARS-CoV-2 receptor, it can be tough to ignore coincidental findings like this when therapeutic options are sorely needed.