By detecting characteristicspectroscopic signatures of nucleic acids, proteins, and lipids, RSnot only distinguishes malignant cells from normal B cells, but alsodiscriminates between HD B-ALL and other molecular subtypes, including TCF3-PBX1, KMT2A-r, BCR-ABL1, and TEL-AML1. The gene discussed is TCF3; the disease is precursor B-cell acute lymphoblastic leukemia.