Although motivated by a series of preclinical studies that showed tumor growth and progression restraining effects of imatinib in different breast cancer models [123–127], clinical trials could not demonstrate consistent and strong clinical efficacy of imatinib or other non-selective PDGFRβ inhibitors in breast cancer, as well as several other solid cancer types (reviewed in detail in [128–130]). Here, PDGFRB is linked to breast cancer.