The viral load is associated with host response figured out by proinflammatory factors. The relative H5N1 viral load in different tissues by determining the ratio of viral HA copy number relative to the copy number of the beta actin gene for a given tissue sample. Tissues of the respiratory system yielded higher copy number ratios than tissues from all to other organ systems with the lower left lung lobe yielding the highest viral load, overall. Interestingly, ureter tissue had the highest viral load of non respiratory system tissues. All other tissues had lower viral loads that were not. Among the digestive system tissues, the viral load in the liver was the highest (See Fig. S1 ). Additionally, we detected mRNA copies of macrophage attractant chemokine CXCL10 (IP-10), macrophage inflammatory protein 3b (MIP-3b), RANTES, tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and TNFa in tissues of brain, respiratory organ, spleen and lymph-node. RANTES and TRAIL can be detected in all selected tissues. MIP-3b is positive in selected tissues except right upper lobe lung with positive b-actin. IP-10 can be determined copies in cerebral context, left upper lobe lung, left lower lobe lung, right middle lobe lung, right lower lobe lung, and aortopulmonary vessel. TNF-a can be showed copies in left upper lobe lung, left lower lobe lung, right middle lobe lung, right lower lobe lung, aortopulmonary vessel and spleen. The correlation among levels of viral load and were showed by Fig. 1 . The Pearson's cross correlation analysis (See Table S1 ) showed that high viral load is associated with high host response figured out by proinflammatory factors (p,0.05) except TNF-a (P.0.05), and the correlation is significant between proinflammatory factors except between TRAIL and TNF-a (p.0.05), and between TRAIL and IP-10(p.0.05) as well.