Table 1 summarizes the clinical and biological features of all CRLF2-positive (CRLF2pos; 29/386) and CRLF2-negative (CRLF2neg; 357/386) BCP-ALL patients at diagnosis and the level of minimal residual disease at days 15 and 33 of the treatment. The gene discussed is OPN1SW; the disease is acute lymphoblastic leukemia.