In the ID8 ovarian cancer model, TAM in peritoneal tumour ascites expresses a high level of folate receptor β (FRβ) and adoptive transfer of FRβ‐specific CAR‐T cells into the tumour‐bearing mice results in destruction of TAMs and delayed tumour growth (Fig. 4c).66 However, further studies are needed to determine whether co‐expression of two different CARs, that is one for TAM and another for cancer cells, enhances therapeutic effects of CAR‐T‐cell transfer therapy. This evidence concerns the gene FOLR2 and cancer.