Comment by kordless

Actually, that's not technically true. FWIU, Lighting could be run on both Bitcoin and Litecoin today, but issues with transaction malleability could cause it to be less than trustworthy, for some use cases. So, Segwit, which fixes transaction mailability by moving the header in the transaction to it's own section, enables a higher trust Lightning network to be deployed, on top of a more trustworthy blockchain.