Furthermore, after 2 weeks of treatment with TAM, the tumour sizes and weights decreased remarkably in the mice injected with MCF7 cells compared with those in the CRB3‐knockdown MCF7 cells group (Figure 2F and G), and CRB3‐knockdown MCF7 cells were more resistant to tamoxifen than control MCF7 cells (Figure 2F and G). Here, CRB3 is linked to neoplasm.