Specialist advice about cancer is now available at a so-called "pop-up" clinic, which has opened in a shopping centre in Croydon.
It is a temporary store to encourage people to ask for help if they think they have got cancer and It will make it easier to get checked out.
This could improve their chances of survival if they have the disease. Piers Hopkirk went for a look around.
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Before the final declaration on Friday, the Conservative candidate looked set to lose the City Hall race to Labour's Sadiq Khan.
The Tooting MP has been the frontrunner in the counting process ahead of Tory challenger Zac Goldsmith.
It's not just London where elections have been taking place today. There were council elections taking place across the home counties.