We fitted distributions to data describing changes in ACE2 expression following treatment with UDCA (Fig 2A and 2B), changes in viral infection given differing levels of ACE2 expression using data from a lung explant study (Fig 2C and 2D), and levels of exposure to SARS-CoV-2 infection, based upon inferred numbers of viruses initiating infection (Fig 2E). Here, ACE2 is linked to infection.