We found that the expression of OSM and its receptor (OSMR) were significantly higher in ER-negative/HER2-negative compared with that of luminal/HER2-positive breast cancers (OSM, p = 3.90 × 10−2; OSMR, p = 2.80 × 10−3) (Figure 4A). This evidence concerns the gene ESR1 and breast carcinoma.