CHI3L1 and neoplasm: In most cases CTCs are scarce and investigations are restricted to single-cell genetic analysis and detection of surface markers or a few cytokines [11] Ubiquitous expression of CHI3L1 in a range of solid tumors, as indicator of early dissemination and lower overall survival, seems to be partially due to CHI3L1-positive CTCs providing an explanation for the correlation of this marker with tumor dissemination [15, 17].