After stimulating with EGF ligand (20 ng ml−1) FLCN null cells (FTC-133 FLCN−/−) and cells expressing tumour-associated mutant forms of FLCN (FTC-133 K508R and FTC-133 dF157) have increased levels of phosphorylated EGFR (pEGFR) compared to cells expressing FLCN WT (Fig. 3a,b). Here, EGFR is linked to neoplasm.