CBL and Methylmalonic aciduria: Released Cbl is exported from the lysosomes via the Lysosome Membrane Chaperone 1 (LMBD1) (54) where it binds to methylmalonic aciduria type C and homocystinuria (MMACHC) proteins (52) and then shuttled to cytoplasmic methionine synthase (MTR) and mitochondrial MUT (Fig. 5).