Usually, methyl groups are present at the carbons C-10 and C-13--an alkyl side-chain at carbon C-17 may also be present.
Methyl groups are present at the carbons C-10-13--an alkyl side-chain at carbon C. This is usually. Methyl groups are present at the carbons C-C-13--an alkyl side-chain at carbon C. This is usually.17 may also be present.