Keyhole limpet hemocyanin (KLH) has been shown to possess immune system-fortifying properties in various animals and human studies, and it has been evaluated in conjunction with MUC-2, a protein present in many cancers, including prostate cancer, and brought into solution with the immunological saponin adjuvant QS21, a tree bark extract (NCT number: NCT00698711 [137]), as well as Thomsen-Friedrich (TF) antigen, a self-antigen present on prostate cancer cells in the presence of QS21 in patients with biochemically relapsed prostate cancer [137]. This evidence concerns the gene MUC2 and Familial prostate cancer.