Guidance on foreigner coming to UK for Leukaemia Treatment

Someone has asked me to find out how they can get the best treatment in the UK for leukaemia. I've been fortunate enough, not to have had any personal experience in being affected by such an issue so I don't know where to begin to get help.

I read that there are 4 main types of leukaemia, but I'm not sure which kind she has. I will come back and add this later when I find out.

Let's say she won't have an issue with being able to afford the best treatment available in the UK and it should be a problem for her to get a VISA for entry to UK to get medical treatment.

So where would she need to begin? I guess she needs a doctor to give her a full check over and make some kind of diagnosis and suggest a recommended path of treatment. Is there a known specialist that is highly recommended that she should go to see?