Progranulin knockdown enhances the toxicity of chemotherapeutic drugs. HCT‐116 cells were transfected with either scrambled (Scr) or progranulin antisense oligonucleotide (ASO) (both used at 200 nm). After 24 h, cells were washed with PBS and cultured with 5‐fluorouracil (5‐FU, 25 μm), oxaliplatin (12.5 μm), camptothecin‐11 (CPT‐11, 2.5 μm), or DMSO (vehicle) for further 48 h. Data indicate the percentage of cell death as assessed by flow cytometry analysis of Annexin V (AV) and/or propidium iodide (PI)‐positive cells and are expressed as mean ± SD of three experiments. Differences among groups were compared using one‐way analysis of variance (ANOVA) followed by Tukey's post hoc test (progranulin ASO‐transfected cells ± chemotherapeutics vs Scr ASO‐transfected cells + DMSO, **P < 0.01, ***P < 0.001; progranulin ASO‐transfected cells + chemotherapeutics vs chemotherapeutics alone, ††P < 0.001, progranulin ASO‐transfected cells + chemotherapeutics vs progranulin ASO‐transfected cells ‡P < 0.05, ‡‡P < 0.01).