The feature of this series of cases was that after the failure of the original chemotherapy regimen, the patients with MSS/pMMR advanced GI tumors were treated using apatinib combined with camrelizumab, which induced a systemic inflammatory response (characterized by sharply increased CRP and emergence of systemic rash, oral ulcer, and gingivitis), and further combination with chemotherapy achieved good results. Here, CRP is linked to Oral ulcer.