Other researchers have been more direct about the potential genetic role: McCoy et al (2020) point to racial genetic variations in the androgen receptor as a contributing causal factor, inferring this from studies implicating the androgen receptor in gender differences in Covid-19 disease severity and mortality, as well as previous work indicating there are racial variations in androgen-mediated conditions such as prostate cancer. This evidence concerns the gene AR and Familial prostate cancer.