Most of these circRNAs were associated with BC known disease genes (AKT1, PIK3CA, PPM1D, SMAD4 and TSG101) or miRNAs (hsa-let-7f, hsa-mir-7, hsa-mir-103a, hsa-mir-135a, hsa-mir-144, hsa-mir-146a, hsa-mir-182, hsa-mir-185, hsa-mir-190a, hsa-mir-204, hsa-mir-216b, hsa-mir-26a, hsa-mir-374b, hsa-mir-378a, hsa-mir-449a and hsa-mir-625). The gene discussed is PIK3CA; the disease is breast cancer.