Second, we found that CCoV-HuPn-2018pp could infect five human cancer cell lines with varying levels of efficiency (Fig. 4B) and confirmed that this infection was not mediated by hAPN as the endogenous hAPN levels in these human cell lines were not correlated with the CCoV-HuPn-2018pp entry levels (Fig. 4E) and anti-hAPN antibodies did not block the entry of CCoV-HuPn-2018pp (Fig. 4F). The gene discussed is ANPEP; the disease is cancer.