(A) Validated screening hits from Elitt et al., 2018 with annotations of subsequently-established inhibitory activity for EBP, CYP51, or sterol 14-reductase. (B) Percentage of MBP+ oligodendrocytes generated from OPCs following treatment with bioactive small molecules at a uniform dose of 10 μM. n=4 wells per condition, except DMSO and amorolfine, n=16 wells, with >1,000 cells analyzed per well. (C) GC-MS based quantification of 14-dehydrozymostenol, zymostenol, and zymosterol levels in OPCs treated for 24 h with the indicated screening hits at 10 μM. n=2 wells per condition. (D) Percentage of MBP+ oligodendrocytes in OPCs treated with climbazole in dose response as shown. (E) GC-MS based quantification of lanosterol levels in OPCs treated with climbazole in dose response as shown. n=2 wells per condition. For percentage of MBP+ oligodendrocytes for all bioactive small molecules that were screened, see Fig. S3. S14R, sterol 14-reductase.