Understanding the distinctive immunomodulatory processes of the breast cancer microenvironment will be crucial for the creation of novel therapeutic approaches. Cav-1's role in BC is still debated because it has been demonstrated to have a dual opposing role, functioning as both an oncogene and a tumor suppressor. Various studies reported the occurrence of a somatic mutation in Cav-1 in patients' primary breast tumors leading to the substitution of a proline amino acid-to-leucine at 132 (P132L) location. Therefore, the current study aims to examine the expression of Cav-1 in tissue samples of patients with breast cancer and assess the incidence of p132L point mutation of the Cav-1 gene in patients with breast cancer. The current study enrolled 50 patients with breast cancer, and the levels of expression of Cav-1 protein were measured by immunohistochemistry. Sequencing of amplified Cav-1 gene in sample groups was done to assess the incidence of a spontaneous mutation (P132L) inside the human Cav-1 in breast cancer patients.  The current results demonstrated the absence of P132L target point mutation in all Cav-1 downregulated Egyptian breast cancer patients (90%). Accordingly, the alteration in the expression level of Cav-1 in tissues of Egyptian patients with breast cancer is not due to the P132L target point mutation, but other factors may contribute to this down-expression.