IGFBP2 and cancer: Western blot analysis revealed differential expression of target proteins in HET-1A, KYSE30, and KYSE450 cells: ATF3 protein was significantly upregulated in cancer cells; BIK expression was elevated in KYSE30 and KYSE450 cancer cells; IGFBP2 expression was lower in cancer cells compared to HET-1A cells, and LY6K expression was reduced in cancer cells; BTG2 protein did not show significant differences between normal and cancer cells (Figure 6).