DPP9 and COVID-19: Other Neanderthal-related haplotypes reported to correlate with the severity of COVID-19 include genetic elements coding for the DPP9 protein (chr19, p13.3 –lead SNP: rs2109069) and the interferon alpha receptor (IFNAR2) protein (coding chr21, q22.1 –lead SNP: rs2236757) (see refs [27, 28]).