TG and hypothyroidism: Since thyroglobulin undergoes intracellular degradation in endolysosomes following endocytosis or macroautophagy-like uptake, a functional role of SPRED3 in regulating vesicle transport or lysosomal processing could explain both the altered expression of autophagy-related proteins and the molecular mechanisms of the observed hypothyroidism in SPRED3 KO mice [13].