Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_31470 ( "Event" real, "Circuit" text, "GT3 Pro Cup Winner" text, "GT3 Pro / Am Cup Winner" text, "GT3 Citation Cup Winner" text, "GT4 Cup Winner" text )

### Question ###
List all GT4 Cup winners played on the Spa-Francorchamps Report.

### Accurate SQL ###

SELECT "GT4 Cup Winner" FROM table_31470 WHERE "Circuit" = 'Spa-Francorchamps Report'