Recent studies showed the expression of S100P was increased in BilIN-2 and -3 as well as cholangiocarcinoma, and Sato et al. proposed the diagnostic algorithm of histological grading of BilIN including the expression of S100P in the cytoplasm that helps the grading of BilIN1–3 [12, 18, 25]. This evidence concerns the gene S100P and cholangiocarcinoma.