Seeking confirmation that these genes were relevant in a physiological setting, we sought to test these genes in dengue patients. Whole blood RNA samples were obtained from ten adult fever patients (age .21 years old) enrolled in the Singapore Early Dengue (EDEN) cohort study in 2005 [22] . Each was PCR diagnosed positive for either dengue serotype 1 or 3 and all showed typical dengue fever symptoms. At the second visit (,5 days after onset of fever, onset of fever considered day 1), their platelet count had dropped below 30 (x 10 3 /ml; range 8-30, mean 20.5), and they were admitted to hospital. When these patient samples were tested for expression of the 95 selected genes by LDA, 67 genes were shown to be differentially expressed comparing blood samples taken at acute fever stage (first visit, 1-3 days after onset of fever) to convalescence (third visit, 3-4 weeks after first visit) (Table S2) .