CTLA4 and neoplasm: According to Yao et al.’s report, PTT is capable of inhibiting metastatic tumor growth by stimulating the host immune system to release tumor antigens into the tumor microenvironment and promoting the expression of tumor‐derived antigens to the T cells.[249] For this reason, PTT is always combined with a cytotoxic T lymphocyte‐associated protein 4 (CTLA‐4) blockade to achieve better therapeutic results.