GPG keys are a vital part of verifying your online identity. As such, securing it from bad actors ensures that no one can impersonate you in your communications with other people.
Most of us are probably guilty of just setting our GPG key up once and then just using it, but here are some tips if you want to lock it down a bit further.
If you have not yet set one up, there is also a link at the start of the article for how to do that.