In contrast, when BC cells were transfected with si-NC, si-circHIAT1, si-circHIAT1+Inh-NC, or si-circHIAT1+miR-19a-3p inhibitor, the silencing of circHIAT1 caused the up-regulation of miR-19a-3p and the down-regulation of CADM2. The gene discussed is CADM2; the disease is breast cancer.