Correlation between ROS levels and proviral loads. Proviral loads (expressed as numbers of viral copies in B cells) were measured by real-time PCR in PBMCs isolated from BLV-infected sheep (n = 13). ROS levels were measured in B cells cultivated for 24 h using the CM-H2DCFDA probe. A correlation coefficient R2 = 0.7764 was calculated. p < 0.001 was determined using the non parametric Spearman test.