Proposed pathway of urinary carnitine loss by cisplatin in wildtype mice (A) but not in Oct1/2(−/−) mice (B). See Discussion for details. Abbreviations: Acox1, acyl-coenzyme A oxidase; Cpt, carnitine palmitoyltransferase; Ctr1, copper transporter 1 (Slc31a1); Cyp2e1, cytochrome P450 isoform 2e1; Il-1β, interleukin-1β; P38, P38 mitogen-activated protein kinase (P38 MAPK, Mapk14); Oct, organic cation transporter; Octn2, novel organic cation transporter 2; Ppar-α, peroxisome proliferator activated receptor-alpha; Pgc1, peroxisome proliferator activated receptor-gamma-coactivator-1 (Ppargc1α); PPRE, peroxisome proliferator response element; ROS, reactive oxygen species; Rxr-α, retinoid X receptor; Tnf-α, tumor necrosis factor-α; Tnfr2, tumor necrosis factor receptor 2 (Tnfrsf1a).