EPCAM and breast cancer: Several EpCAM-targeting DARPins conjugated to PE40 (ETA”) were developed and showed strong anti-tumor responses in vivo: Ec4-ETA” [77] in HT-29 colon cancer cells and in SW2 small cell lung carcinoma xenografts, Ec1-ETA” and its PEGylated version PEG20kDa-Ec1-ETA” [78] in MDA-MB-468 breast cancer xenografts.