TAP1 and hepatocellular carcinoma: These findings were in the line with an early report that demonstrated TAP1 as a critical factor in the mediation of drug resistance by SHH in pancreatic ductal adenocarcinoma.21 The higher frequency of increased TAP1 levels in HCC specimens with a normal serum AFP level may indicate that TAP1 expression is associated with poorly differentiated pathologic classification (all in II‐III classes), although a large number of HCC specimens are needed to allow such a correlation analysis along with other markers, such as glypican‐3 (GPC‐3), (Table S5) currently used in clinics for HCC detection.