CDKN1B and breast cancer: Based on the results presented above, a schematic diagram is presented in Figure 8 that outlines the effects of 4-hydroxitamoxifen, moderate increase in the concentration of D-(+)-glucose and deficiency of D-(+)-glucose or L-leucine on the pathways #1 and #2 of the upstream molecular signaling pathways of the expression of p27 in human breast cancer cells in vitro.