PECAM1 and acute myeloid leukemia: In vivo treatment of MllPTD/WT/Flt3ITD/ITD AML mice with TNFα-neutralizing Ab (anti-TNFα; MP6-XT22, Biolegend; 1 mg/day, ip, 4 times/week for 3 weeks) [27] rescued the loss of CD31+Sca-1high ECs and arterioles (Fig. 2g, h) otherwise observed in the leukemic BM niche.