All four Arabidopsis CYP81F gene products had the capacity to modify the indole GSL structure. CYP81F1; CYP81F2; and CYP81F3 but not CYP81F4 catalyzed the conversion of indol-3-yl-methyl GSL (I3M) to 4-hydroxy-indol-3-yl-methyl (4OH-I3M) and all four CYP81Fs converted I3M to 1-hydroxy-indol-3-yl-methyl GSL (1OH-I3M) (Pfalz et al. 2011)