PTTG1 and hepatocellular carcinoma: Although human T-cell leukemia virus 1 infection pathway has not been reported to be linked to HCC, but the upregulation of modular genes involved in this pathway such as CDC20, MAD2L1, and PTTG1 have been confirmed to promote HCC development and progression (Cho-Rok et al., 2006; Li et al., 2014; Li Y. et al., 2017).