ESR1 and breast cancer: The comparison of breast cancer markers between Wood, PB, and the canonical SK‐BR‐3, MCF‐7, and MDA‐MB‐231, showed how the ERα + Wood cells have much lower levels of ERα than the classically used MCF‐7, whereas PB resembles a triple‐negative subtype, but with lower proliferation rate than the MDA‐MB‐231 (Supplementary Figure 5).