PoTFPI-1 and PoTFPI-2 expression in flounder tissues. PoTFPI-1 and PoTFPI-2 expressions in the brain, muscle, spleen, gill, head kidney, blood, intestine, heart, and liver of flounder were determined by quantitative real time RT-PCR. For convenience of comparison, the expression level in the brain was set as 1. Data are the means of three independent assays and presented as means ± SEM (N = 3). N represents the number of times the experiment was performed.