Disclosed is the in vitro use of at least one lectin which recognises the fucose alpha(1-2) galactose unit for labelling cancer stem cells of organs involved in respiration, in order to obtain labelled cancer stem cells of organs involved in respiration, in a biological sample. In one particular embodiment, the at least one lectin is chosen from the lectins Ulex Europaeus agglutinin 1 (UEA-1) or the homologue thereof, Trichosanthes japonica agglutinin II (TJA-II), Agaricus Bisporus agglutinin (ABA), Amaranthus Caudatus agglutinin (ACA), jacalin, Griffonia Simplicifolia lectin I (GSL-I) and Griffonia Simplicifolia lectin II (GSL-II). In one particular embodiment, the organ involved in respiration is chosen from the lungs, the larynx, the pharynx, the mouth, the nose, the throat, the tongue, the sinuses, the trachea and the saliva glands including the tonsils and the parotid gland.

Disclosed are biomarkers for Barrett's esophagus and esophageal adenocarcinoma, and uses thereof, such as in methods for detecting the presence, and monitoring progression, of Barrett's esophagus and esophageal adenocarcinoma. Also disclosed are methods for treating and methods of monitoring the treatment of Barrett's esophagus and esophageal adenocarcinoma, as well as kits and compositions for use in such methods.