CREATE TABLE "united_states_house_of_representatives_e" (
  "district" text,
  "incumbent" text,
  "party" text,
  "first_elected" real,
  "result" text
);

Question: result is lost re-election republican gain, what is the district?
SQL: SELECT "district" FROM "united_states_house_of_representatives_e" WHERE "result"='lost re-election republican gain';