Related Clues:

• Major medical grp
• Start of many a 'Jeopardy!' response
• '___ knew?'
• Doctor of British sci-fi
• First baseman, to Abbott and Costello
• Second word of a Hemingway title
• Question of recognition
• ''What guy?''
• 'Tommy' group, with 'The'
• "Tommy" group, with "The"
• 'I've never heard of that person'
• First of a journalist's five W's
• "___ do you think you are?"
• Unix command for listing logged-in users
• Hemingway's "For __ the Bell Tolls"