Table:
0
A
B
C
D
E
F
1
District
Incumbent
Party
First elected
Result
Candidates
2
Illinois 3
Fred E. Busbey
Republican
1946
Lost re-election Democratic gain
Neil J. Linehan (D) 52.9% Fred E. Busbey (R) 47.1%
3
Illinois 5
Martin Gorski Redistricted from 4th
Democratic
1942
Re-elected
Martin Gorski (D) 72.4% John L. Waner (R) 27.6%
4
Illinois 14
Chauncey W. Reed Redistricted from 11th
Republican
1934
Re-elected
Chauncey W. Reed (R) 68.3% Richard Plum (D) 31.7%
5
Illinois 15
Noah M. Mason Redistricted from 12th
Republican
1936
Re-elected
Noah M. Mason (R) 56.4% G. M. Wells (D) 43.6%
6
Illinois 17
Leslie C. Arends
Republican
1934
Re-elected
Leslie C. Arends (R) 62.8% Carl Vrooman (D) 37.2%
7
Illinois 18
Everett Dirksen Redistricted from 16th
Republican
1932
Retired Republican hold
Harold H. Velde (R) 52.1% Dale E. Sutton (D) 47.9%
8
Illinois 20
Sid Simpson
Republican
1942
Re-elected
Sid Simpson (R) 53.1% Henry D. Sullivan (D) 46.9%
9
Illinois 20
Anton J. Johnson Redistricted from 14th
Republican
1938
Retired Republican loss
Sid Simpson (R) 53.1% Henry D. Sullivan (D) 46.9%
10
Illinois 26
C. W. Bishop
Republican
1940
Re-elected
C. W. Bishop (R) 51.9% Kent E. Keller (D) 48.1%

Questions and formulas:
Question: Who was the incumbent in the Illinois 17 district?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:F1,A1="Illinois 17"),2))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:F10,A2:A10="Illinois 17"),2))
Level: medium