CXCL8 and neoplasm: All clonal subcultures ofHT29 showed high homogeneous outputs of IL-8 while the SW48 cell line did notreach detectable levels in any experiment, and CaCo2 subcultures showed aroundone half of the production when compared to the levels attained by HT29 cellscultured at identical density for the same period of time (Figure S1).Microenvironment conditions and therapy may modify the ability of tumor cells toproduce IL-8.