Finally, to validate whether our observations are pertinent in CS patients, we generated pools of patient-derived LBLs (see “Materials and methods”) that are wild-type for SEC23B (LBL-SEC23B-WT) or harbouring SEC23B p.V594G heterozygous mutation (LBL-SEC23B-V594G), respectively. This evidence concerns the gene SEC23B and Cowden syndrome 1.