MUC5AC and mucinous adenocarcinoma: This is caused by various factors, including: 1) The intrinsic characteristics of tumors: When tumors are located at greater depths or display uneven surfaces, acquired SWE images can easily become distorted; 2) Varied pathological changes in different types of breast tumors: For instance, mucinous carcinoma is primarily composed of mucin, rendering it relatively less rigid; 3) Differences in ROI selection: Presently, two predominant ROI selection strategies are employed within China.