Calcyclin-binding protein (CacyBP/SIP), a 30 kDa protein identified on the basis of its ability to interact with S100A6 in a Ca2+-dependent manner in Ehrlich ascites tumour (EAT) cells [8], was previously thought as a multiple-drug resistance (MDR)-related molecule in gastric cancer in our laboratory [9]. Here, S100A6 is linked to gastric cancer.