Relation between protein and RNA regulation. (A) HuR interactome: our predictions, made using catRAPID , indicate that expression levels of RNA targets change upon HuR knock-down (log-fold changes, LFC), in agreement with experimental evidence  (P < 10-5; Kolmogorov–Smirnov test). (B) LIN28B interactome: RNA targets are downregulated upon LIN28B knock-down (LFC), as reported in a previous study  (P < 10-2; Kolmogorov–Smirnov test). In this analysis, the prediction of the interactions was highly significant (HuR: P < 10-8; LIN28B: P < 10-3; Fisher’s exact test). Our results indicate that changes in protein expression influence the abundance of RNA targets to a significant extent. HuR, human antigen R; LFC, log-fold change; LIN28B, lin-28 homolog B.