Table 1 summarizes the staining patterns for all cases. A significant difference was observed between TNBC and luminal A groups, with high-intensity staining less frequent and negative or low staining more prevalent in TNBC (Table 1). In non-cancer areas of both TNBC and luminal A, SPRED2 was detected in the cytoplasm (Figure 7B, left). In cancer areas, SPRED2 immunohistochemical staining patterns differed significantly between TNBC and luminal A groups (Figure 7B, right; Table 2). Here, SPRED2 is linked to cancer.