Vallera and colleagues showed that the fusion protein CD133KDEL, consisting of a CD133-specific scFv fragment and a deimmunized form of pseudomonas exotoxin A, has a high antitumor and cytotoxic activity in various xenograft cancer models, including head and neck cell carcinoma [118], breast carcinoma [119], and ovarian cancer [120]. The gene discussed is PROM1; the disease is breast carcinoma.