Database: thrombosis_prediction
Question: Please list a patient's platelet level if it is within the normal range and if he or she is diagnosed with MCTD.
SQL: SELECT T2.PLT FROM Patient AS T1 INNER JOIN Laboratory AS T2 ON T1.ID = T2.ID WHERE T1.Diagnosis = 'MCTD' AND T2.PLT BETWEEN 100 AND 400