They are written differently based on exact intent. But here is what I think you wanted.
Code:
#showtooltip
/cast [mod:alt,mod:ctrl,@player][mod:ctrl,@mouseover,help,nodead][mod:ctrl,@target,help,nodead][mod:ctrl,@player]Remove Curse;[mod:alt,@player][@mouseover,help,nodead][@target,help,nodead][@player]Abolish Poison
Like this, if some condition fails it moves to next, you can also write it in a way that failing a condition makes it stop.
I added alt key so you can bypass conditions and cast on self right away if needed.