How to reload current page in Express.js?

I’d just like to add that in the version 4.x of Express you can use

res.redirect('back');

to automatically redirect back to the page the request came from.
This is the equivilant of

res.redirect(req.get('referer'));

that is mentioned in Peter Lyons answer

See also: http://expressjs.com/api.html#res.redirect