KCNK9 and oral cavity squamous cell carcinoma: In oral squamous cell carcinoma (OSCC), the protein expression of KCNK3 (TASK1 or K2P3) and KCNK18 (TRESK or K2P18), which belong to the family of tandem pore domains in weakly inward rectifying K+ (TWIK) channels, was found to be decreased in rat tumors and cancer patient tissues compared to normal samples, unlike KCNK9 (TASK3 or K2P9), which was found to be overexpressed in the OSCC samples compared to normal tissue [84].