We measured CD68, CD163, and MMP-9 protein expression in formalin-fixed paraffin-embedded tissues of breast carcinomas represented in tissue microarray format using multiplexed quantitative immunofluorescence (QIF) in two independent Yale cohorts: cohort A—n = 398, estrogen receptor–positive (ER+) and ER− cases—and the triple-negative breast cancer (TNBC)-only cohort B (n = 160). This evidence concerns the gene MMP9 and triple-negative breast carcinoma.