Correlation between HTLV-1 proviral load and HTLV-1 mRNA load in HTLV-1 infected individuals. A. The HTLV-1 HBZ mRNA load was significantly correlated with HTLV-1 proviral load in HAM/TSP patients alone (P = 0.0005, r = 0.470 by Spearman rank correlation analysis), HCs alone (P = 0.0013, r = 0.528) and all groups combined (P < 0.000001, r = 0.686) but not in ATL patients (P = 0.300, r = 0.345). B. The tax mRNA load correlated with the HTLV-1 proviral load in HCs (P = 0.045, r = 0.444), ATL patients (P = 0.045, r = 0.673) and both group combined (P < 0.01, r = 0.365) but not in HAM/TSP patients (P = 0.411, r = 0.210). The zero value of tax gene transcripts did not appear in the figures. Correlations were examined by Spearman rank correlation analysis.