Of the results obtained at mRNA levels in the biopsies of GBM patients, three distinct subpopulations were evidenced in the T98 and U251 cell lines: TRPML2-positive/TRPML1-negative, TRPML1- and TRPML2-positive, and TRPML1- and TRPML2-negative (Figure 2B). The gene discussed is MCOLN1; the disease is glioblastoma.