Anyone seen that giant sign on a hill saying "Save the NHS" in North East London??

Last week I was driving through North East London and saw a huge hill with a giant sign saying "Save the NHS" (it reminded me a bit of the Hollywood Sign). It's quite memorable and I want to take some photos but I forgot to note where this was. Does anyone know anything about where this sign is? Can't seem to find anything online on its existence. I think it may have been on the North Circular/M11 but I'm not sure