The KEGG pathway frequency analysis revealed the top 7 changed pathways between the control-TuD- and let-7 (-7a, -7b, -7e, and -7i) groups, which included cancer, cytokine-cytokine receptor interaction, and the PI3K-AKT and MEK/ERK signaling pathways (Fig. 2D). This evidence concerns the gene PIK3CD and cancer.