In a different study, peri-tumoral co-delivery of anti-PD-1 + CTLA-4 mAb entrapped by an in situ crosslinked thermosensitive hydrogel that gradually released the mAb at physiological temperatures, significantly stunted tumor growth compared to peri-tumoral co-delivery of free anti-PD-1 + CTLA-4 as reported by Kim et al. Moreover, while the hydrogel anti-PD-1 + CTLA-4 group did not exhibit any signs of liver toxicity as measured by serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, the free drug group had elevated ALT/AST levels indicative of toxicity. This evidence concerns the gene GPT and neoplasm.