CREATE TABLE table_37901 ("District" CLOB, "Incumbent" CLOB, "Party" CLOB, "First elected" CLOB, "Result" CLOB)

Which Incumbent has a Result of retired democratic gain?
SELECT "Incumbent" FROM table_37901 WHERE "Result" = 'retired democratic gain'
SELECT "Incumbent" FROM "table_37901" WHERE "Result" = 'retired democratic gain'