We also observed that the SMAD5 overexpression could significantly reverse the aggravation by circRHOT1 knockdown of BC sensitivity to NK cells, as indicated by the results from the calcein release assay (Figure 7(g)), perforin polarization assay (Figure 7(h)), and conjugation assay (Figures 7(i) and 7(j)). Here, SMAD5 is linked to breast cancer.