ESR1 and breast carcinoma: Higher SUVmax of [18F]FDG were observed in all cases, compared with [68Ga]Pentixafor (mean SUVmax of 16.2 vs. mean SUVmax of 3.6; p < 0.05).(Figure 2) This study did not reveal any significant correlation between [68Ga]Pentixafor uptake and breast cancer prognostic factors (ER, PR, or HER2 status), proliferation index, or tumor grade.