Consequently, by day 5, PEC-B cells became the PEC subtype with the highest expression of Aldh1a2. PEC-B cells are a minor PEC subtype in healthy mice but numbers increase progressively and become the major PEC subtype in anti-GBM glomerulonephritis mice by day 5 [9]. The gene discussed is ALDH1A2; the disease is glioblastoma.