I am new to the forum but have been using Excel for about a decade now though I have never gotten into formulas very deeply. I have a simple problem that I need help with from someone more expert then I. The problem is how to compare two cells each with two letters and mark in a third cell on the same row whether the two cells share any letters in common. for example:

AA AT
CC TT
TT CT
GG GG

I want to have rows 1 and 3 show a match since row 1 cells share an A and row 3 shares a T.
Row two should show no match since its cells share no letters.
The bottom row should, of course, also show a match since all letters are shared

I have vast columns of these genotypes and need for Excel to tell me at a glance which cells share letters and which don't.
I also need the "match" or "no match" in a third column to allow me to sort by that column.
Thanks in advance for any solution.