We recently reported a related study using sulfonyl fluoride probes to advance a series of correctors of trafficking mutations in the creatine transporter SLC6A8 that cause creatine transporter deficiency (CTD).117 A hit generation screen of a library of reactive affinity probes (RAPs) incorporating diazirine photo-crosslinking and click handle functionalities identified 40 specific binders of SLC6A8 in cells. Here, SLC6A8 is linked to X-linked creatine transporter deficiency.