However, more recent studies of 31 ctns mutations (using constructs that translocate to the plasma membrane) have indicated that some ctns mutations that cause infantile cystinosis (including ctns S298N and ctns W182R) permit normal cystine transport activity to be retained, whereas several mutations causing juvenile cystinosis (including ctns N323K and ctns K280R) result in a complete loss of cystine transport activity [1]. Here, CTNS is linked to cystinosis.