We next addressed the activity of y+L in CHO cells transfected with the plasmid bearing the wild-type (w/t) sequence of SLC7A7 or with the mutations either carried by the three LPI patients as in Fig. 1 (LPI1, LPI2 and LPI3) or described in literature, namely LPI4; CHO cells carrying empty vectors were employed for comparison (negative). This evidence concerns the gene SLC7A7 and lysinuric protein intolerance.