A TI{CRIMIC.TG4.0} DNA cassette has been inserted into Arl4, in a coding intron, and is predicted to gene trap a subset of the annotated transcripts of the gene (insertion is in a coding intron of two annotated transcripts and in an intron in the 3'UTR of one annotated transcript). The TI{CRIMIC.TG4.0} cassette was inserted via the CRISPR/Cas-9 drop-in technique, using a dsDNA donor vector with homology arms of length 200bp. The sgRNA sequence used to target the gene was: GGCTCTATGTAAGAAGTGGGTGG.