PPARG and rectal cancer: For PPARG rs1801282 C>G polymorphism, the power value (α = 0.05) was 0.529 in G vs. C genetic model and 0.810 in GG/CG vs. CC genetic model among overall CRC cancer group, 0.717 in G vs. C genetic model, 0.791 in GG/CG vs. CC genetic model, 0.528 in CG vs. GG/CC genetic model and 0.562 in CG vs. CC genetic among colon cancer group, and 0.474 in G vs. C genetic model, 0.554 in CG vs. GG/CC genetic model and 0.552 in CG vs. CC genetic among rectum cancer group.