PAX5 and acute myeloid leukemia: Of note, components of canonical WNT signaling (FZD8, LEF1, WNT10B, AXIN2), the ETS1 transcription factor and its co-activator PAX5 [4], and the stem-cell and fetal B cell developmental gene LIN28B [5, 6] are expressed at distinctly higher levels in infants compared to older children with AML (Fig 2A, inset shows high correlation between PAX5 and ETS1 mRNA levels).