SOCS1 and acute lymphoblastic leukemia: To confirm the gene expression changes, we treated CRLF2 B-ALL cells isolated from PDX-1 and PDX-2 as well as Mutz-5 and Call-4 cells with 15,000 pg/mL for 3 days and assessed the SOCS protein expression levels (SOCS1 and SOCS3) using flow cytometry.