When modeled as a continuous variable, Staphylococcus abundance showed significant correlations in TNBC with reduced M0 macrophages and increased monocytes, and a near-significant association with activated CD4 memory T cells (p = 0.0859; Supplementary Fig. 13 , Additional file 1).
Although these additional correlations did not reach statistical significance (adjusted p-values > 0.4), the TNBC-restricted pattern is consistent with a shift toward a more pro-inflammatory immune environment associated with Staphylococcus in TNBC.
Interestingly, in human breast tissues, the abundance of Staphylococcus consistently showed a decreasing trend with advancing cancer stages across various breast cancer subtypes (Fig. 4 b).