In conclusion, the mAb GGSK-1/30 represents a platform, which can be used (i) as a diagnostic tool for the detection of hu(TA)MUC1 in early breast cancer diagnosis, (ii) as a prognostic biomarker, (iii) as a companion diagnostic during therapy and (iv) in future perspective in radioimmunotherapy. Here, MUC1 is linked to breast carcinoma.