MMP1 and breast cancer: As for the molecular breast cancer subtype, upregulated MMP1 was significantly related to worse OS in luminal A and TNBC subtype patients (HR = 1.72; 95% CI, 1.2 - 2.47, p = 0.0028; HR = 1.65; 95% CI: 1-2.71, p = 0.048), while not correlated to OS in luminal B and HER2-positive subtypes of BC patients (HR = 1.3; 95% CI: 0.9-1.89, p = 0.16; HR = 0.57; 95% CI: 0.29-1.11, p = 0.094) (Figure 4A–4D).