Additionally, we also checked the ability of the mutant protein to be a
cell-penetrating peptide sequence. As depicted in Table 7, the mutation
of Arginines on the C- and N-terminal of the homeodomain leads to a
decrease in confidence of the peptide to cell penetrating. As previously
mentioned, cellular uptake peptides is increased due to multiple
arginines by attaching fatty acid to N-terminal of the peptide85. It has also been
mentioned that the presence of more than six arginine residues is
critical for efficient cell-penetrating functions85. The ability of
these peptides for convenient cellular uptake needs to be studied in
detail to find their efficacy as therapeutic agents targeting IRX
homeodomain family in different cancers.