Conclusion: Among all types of breast cancer, the expression of CTLA-4 was the highest in TNBC.CTLA-4 in TNBC can be regulated by hsa-mir-92a to form ceRNA networks and influence the prognosis of TNBC patients through the leukocyte differentiation, regulation of leukocyte activation and T cell activation pathway. Here, CTLA4 is linked to breast carcinoma.