Answer:
The slc7a9 (Solute Carrier Family 7 Member 9) gene encodes for a protein that plays a critical role in the transport of cysteine in the kidneys, thereby a mutation in this gene may lead to health problems related to the urinary system. On the other hand, the SLC3A1 gene encodes a protein subunit which is required to form a transporter complex that is not involved in the transport of cysteine.
