GPC3 is expressed in pluripotent cells and cancer cells [75–77]. RSPO1 has been demonstrated to commit to the specification of germ cells, and RSPO2 plays a role in craniofacial, limb, and branching development [78, 79]. WNT16 is involved in the specification of hematopoietic stem cells [80]. This evidence concerns the gene RSPO2 and cancer.