HDAC1 and hepatocellular carcinoma: From the mass spectrometry CD13 interaction list, HDAC5 (Histone Deacetylase 5) family proteins (HDAC5, HDAC1, and HDAC6) were listed as several of TOP10 CD13 interacting proteins, which garnered our attentions (Table S5), suggesting the importance of HDACs in CD13‐regulated signaling event in HCC.