A convenient set consisting of eight inhibitors useful for studying JAK/STAT signaling pathway. The inhibitors are: 5 mg of AG 490 (Cat. No. 1570-5), 5 mg of CP-690550 (Cat. No. 1622-5), 500 µg of Lestaurtinib (Cat. No. 1805-500), 5 mg of LLL12 (Cat. No. 1792-5), 50 mg of Pimozide (Cat. No. 1887-50), 5 mg of Stat3 Inhibitor, S3I-201 (Cat. No. 1775-5), 5 mg of Stat3 Inhibitor, Celll-Permeable (Cat. No. 1778-1), and 5 mg of WP1066 (Cat. No. 1809-5).