In the case of breast cancer, [99mTc]Tc-iFAP showed a significant positive correlation between the T/Bp value of the primary tumors and the molecular subtype (Pearson correlation coefficient: r = 0.8085), where HER2+ and Luminal B HER2+ enriched subtypes showed the highest T/Bp ratios (Figure 7). Here, ERBB2 is linked to breast carcinoma.