Cables are fast disappearing on the larger modern motorcycles, but there are still plenty around and most riders ignore them until they break or cause a problem. This is partly because modern Teflon-coated cables have an amazing lifespan and need very little maintenance.
But there’s still a substantial gain in performance and durability available from steel-wound cables if they’ve lubed regularly, and there’s still plenty of steel-wound cables in use. You'll be amazed at how much lighter a throttle or clutch will feel if it’s given a good dose of lubrication, especially if it’s been allowed to gunk up.
Just to cover our bases, check your owners’ manual for advice on whether or not the cables on your motorcycle need lubrication. But if you have a small-capacity-motorcycle you can be pretty sure they need regular lubrication.
We see plenty of people using products like WD40 for lubricating cables and it isn’t ideal for the purpose. We like to purge and crud with WD40, then lubricate the cable with a purpose-specific cable lubricant. You can get one of those from most automotive mechanical shop, too.