These ADCs have been directed against specific antigens expressed in several solid tumors including ovarian cancer, among which the most investigated are cancer antigen 125 (CA125 or MUC16) [57, 67, 68], NaPi2b [58, 59, 69–71], Trop2 [72], TF [73–75], protein tyrosine kinase 7 (PTK7) [76], CD166 and Notch3 [77]. The gene discussed is PTK7; the disease is ovarian cancer.