As EpCAM is currently the most widely used cell surface marker for antibody-based isolation techniques of CTCs, herein we compared mHsp70 and EpCAM expression by tumor cell lines derived from different entities including breast, lung, melanoma, pancreas, cervix, colon, brain, and squamous cell carcinoma of the head and neck by flow cytometry. Here, EPCAM is linked to squamous cell carcinoma.