We first confirmed that CDX-3379, which decreases pHER3 levels (see above, Figs. 2d and  3a), also disrupts the association between HER3 and the p85 regulatory subunit (Fig. 3a), in a PIK3CA wild type HNSCC cell line (Cal27). The gene discussed is ERBB3; the disease is head and neck squamous cell carcinoma.