ADORA3 and hepatocellular carcinoma: Other negative T cell inhibitory molecules, including natural killer cell receptor CD244 [44], lymphocyte-activation gene 3 (LAG-3) [45], T cell immunoglobulin domain and mucin domain-3 (Tim-3) [46], CD160 [47], and adenosine A3 receptor (A3AR) [48] are related to T cell dysfunction in chronic hepatitis and HCC (Figure 1).