KISS1 and hepatocellular carcinoma: Surprisingly, according to the databases in the HPA database, except for breast duct carcinoma (CAB017775), no KISS1 protein was detected in cancers like colon adenocarcinoma (HPA035542), hepatocellular carcinoma (HPA035542), lung adenocarcinoma (HPA035542), and prostate adenocarcinoma (HPA035542) (Figure 1d).