AKT1 and colorectal carcinoma: Similarly, Singh et al., by utilizing shRNA-induced suppression of ALDH1B1 expression in a 3-D spheroid growth model and a nude mouse xenograft tumor model, demonstrated the crucial role of ALDH1B1 in formatting CRC tumors through the implication of CSC-related Wnt/β-catenin, Notch and PI3K/Akt signaling pathways [8].