Unfortunately, we did not perform an exploratory analysis to study some predictors of efficacy; indeed, two prior studies have investigated the role of molecular predictors of regorafenib efficacy in the REGOMA trial: a mini-signature of 2 gene transcripts (HIF1A, CDKN1A), 3 miRNAs (miR-3607-3p, miR-301a-3p, miR-93-5p) [26] and phosphorylated acetyl-CoA carboxylase [27] were associated with prolonged survival in recurrent glioblastoma patients treated with regorafenib. Here, CDKN1A is linked to glioblastoma.