CREATE TABLE table_4258 ("Name" CLOB, "Family name" CLOB, "Receptor" CLOB, "Coreceptor" CLOB, "Property" CLOB, "Chromosomal location" CLOB)

Which chromosomes have an unknown property?
SELECT "Name" FROM table_4258 WHERE "Property" = 'Unknown'
SELECT "Name" FROM "table_4258" WHERE "Property" = 'Unknown'