CircRNA expression in acute leukemia cell lines and decreased cell viability upon circZNF609 silencing in T-ALL in vitro. (A) CircRNA expression quantification by qRT-PCR in a panel of 13 acute leukemia cell lines of the T-cell, B-cell, and myeloid lineages (mean ± standard error of 2^−ΔCT in 4 replicates per cell line). As indicated in the legend, T-ALL, B-ALL, AML cell lines are shown in different colors, and the oncogenic group for T-ALL cell lines is specified, when available (human T-ALL cell lines database: https://humantallcelllines.wordpress.com). (B) Efficient circZNF609 silencing was obtained in the ALL-SIL cell line upon transfection with a specific siRNA (mean ± standard error of relative quantification in 3 independent experiments). (C) Low proliferation and cell viability (metabolic proliferation assay) in ALL-SIL cells with reduced expression of circZNF609 compared with control, at 24 and 48 hours after transfection and seeding (mean ± standard error of 3 independent experiments). ***, **, and * indicate P < .001, <.01, and <.05, respectively (Mann-Whitney U test). B-ALL, B-cell acute lymphoblastic leukemia.