Statistical analysis. Data parameters were plotted as mean ± s.e.m. Student's test was used to determine significance at P < 0.05. The 2011 Retrovirology Prize winner Masao Matsuoka: forward looking and antisense Masao Matsuoka wins the 2011 Retrovirology Prize. LTR DNA sequence of the HTLV-1 provirus is preferentially methylated while the 3' LTR of the provirus is not. His work in this area is independent of and contemporaneous with similar observations made in human immunodeficiency virus type 1 (HIV-1) research and has added to our insights on how retroviral latency is achieved and how it might be thwarted by employing targeted therapeutic agents.