a, Ranking of expression change of E3 ubiquitin ligases (n = 213 ligases) in patients with lung cancer. Data were generated by normalizing individual expression of E3 ligases in tumour samples to their matched normal expression, as reported by the TCGA. Data are plotted in descending order on a log2 scale. TRIM21, red arrows. Right, a summary table of the ranked ligases is shown. Integrated from 20 datasets included in the LCE29. Genes targeted by shRNA are indicated, and TRIM21 is highlighted. b, Screening of the 18 most consistently downregulated E3 ligases, according to LCE, for their effects on PFKP expression. Abundance of PFKP relative to GAPDH is summarized as a bar chart. The experiment was performed once. TRIM21 (red) is the only one of the tested ligases, the depletion of which leads to an increase in PFKP expression. c, Abundance of TRIM21 in untransformed HBECs and NSCLC cells. Representative data from two independent experiments. d, Abundance of polyubiquinated PFKP in HEK293 cells without (control) and with overexpression of TRIM21–GFP. Representative data from two independent experiments. e, Abundance of PFKP in transformed H2009 cells upon CRISPR-based knockout (KO) of TRIM21. Representative data from two independent experiments. f, Abundance of PFKP after treating HBEC76 cells with AKT inhibitor X (AKTi) (10 μM) for 15 h. Representative data from two independent experiments. g, Abundance of PFKP(S386A)–GFP, which cannot be phosphorylated by AKT, compared to control on stiff and soft substrates. The experiment was performed once. In e, f, protein abundance was normalized to the abundance of β-actin, and in b–d, g to the abundance of GAPDH.