Investigators have found from previous research that they can put a new gene into T cells that will make them recognize cancer cells and kill them. In preclinical studies, the investigators made several genes called a chimeric antigen receptor (CAR), from an antibody called GC33 that recognizes glypican-3, a proteoglycan found on solid tumors (GPC3-CAR). This study will test T cells genetically engineered with a GPC3-CAR (GAP T cells) in patients with GPC3-positive solid tumors.