There is growing evidence of the involvement of Tmem100 in controlling developmental proliferation and differentiation.65 For instance, Tmem100 is involved in the pathways activated by the TGFβ/BMPs/activin family of signaling molecules that are critical in developmental cellular differentiation.15,31,42,47,53 Tmem100 has also been linked to cell proliferation and apoptosis of various tumor cells and tumor-derived neuronal cells. Here, CLN5 is linked to neoplasm.