CKAP4 and intrahepatic cholangiocarcinoma: In view of previous findings, the serum content of CKAP4 in ICC (Li et al., 2013), renal cancer (Sun et al., 2017), glioma (Lu et al., 2018), bladder cancer (Shahjee et al., 2010), and other cancers should be evaluated and its diagnostic value should be assessed in further studies.