Chemotherapy is the standard first‐line treatment for patients with metastatic CRC.[52, 53] 5‐fluorouracil (5‐FU) is a fundamental component of chemotherapeutic agents for palliative and adjuvant treatments of CRC.[54, 55] Therefore, we conducted a treatment that combined 5‐FU chemotherapy with PCSK9 inhibition and anti‐PD‐1 immunotherapy in the MSS CRC mouse model (Figure 7E). Here, PDCD1 is linked to colorectal carcinoma.