INSTR for a case statement

I would like to search for words within a cell and highlight accordingly.
Below is a sample of what I have. I have tried to use the INSTR but cannot seem to get it to work. The cell contents are similar to the following

2.3 PMI
3.4 UG
3.5 PMI & UG

    For Each Cell In Rng1
        Select Case Cell.Value
        'UG
        Case "UG"
            Cell.Interior.ColorIndex = 4
            Cell.Font.Bold = True
        'PMI and GE
        Case "PMI", "UG"
            Cell.Interior.ColorIndex = 5
            Cell.Font.Bold = True
        'PMI and UG