To confirm and extend earlier observations regarding the dependency of the Areg HS-binding domain for signaling (Fig. 1A)12,13, we performed experiments using the Lewis lung carcinoma (LLC) mouse epitheloid cancer cell line, which has high expression of HS and EGFR15,16, using known HS signaling inhibitors. The gene discussed is AREG; the disease is Carcinoma, Lewis Lung.