>90% power to detect the differences observed with our sample size. The percentage of TNFR1_Δ6 transcript level variation accounted for by genotype at rs1800693 was estimated by least-squares regression analysis at 67, 52 and 55% for the CD14+ monocytes, polymorphonuclear cells and CD3+ T cells, respectively. Linear regression analysis was used to quantify the correlation in TNFR1_Δ6 transcript levels between the different immune cell subsets. For all regression analyses there was no significant departure from linearity (P>0.05) as determined using a runs test. For the immune cell TNFR1 surface expression, using a Bonferroni correction (considering six independent hypotheses for six independent immune cell subsets), the significance threshold was P = 0.008; at this threshold we had >80% power to detect a 50% difference between the homozygous groups, given our sample size. For the statistical analysis of the confocal colocalization quantification, two-tailed, paired Student’s T tests were performed. For all other analyses, two-tailed, unpaired Student’s T tests were performed. For all Student’s T tests a 5% significance threshold was used.
