Name the regions for usf45
CREATE TABLE "table1_21530474_1" (
  "chassis_code" text,
  "model_no" text,
  "production_years" text,
  "drivetrain" text,
  "transmission" text,
  "engine_type" text,
  "engine_code" text,
  "region_s" text
);
SELECT "region_s" FROM "table1_21530474_1" WHERE "chassis_code"='USF45';