To examine the RAC1 splicing changes in lung cancer, we analyzed the inclusion levels of RAC1B exon 3b (percent‐spliced‐in, PSI) using RNA sequencing (RNA‐Seq) data of LUAD patients from TCGA and an independent FUSCC cohort.[28]RAC1B exon 3b inclusion levels significantly increased in tumor tissues relative to adjacent non‐tumor tissues in both datasets (Figure 1B). Here, RAC1 is linked to lung carcinoma.