BCR and precursor B-cell acute lymphoblastic leukemia: Besides BCR-ABL fusion protein, JAK/STAT pathway proteins, FLT3 receptor, MAPK pathway proteins, precursor-B-cell receptor (pre-BCR) or the ubiquitin-proteasome system have been proposed as potential targets for different B-ALL subtypes, increasing the armamentarium of potential targeted therapies for this disease (Kuhlen et al., 2019).