Clarissa Cassol's study showed limited PD-1 staining in T cells for acute interstitial nephritis (AIN) and lupus nephritis patients, while Tella Sadighpour's study identified acute tubulointerstitial nephritis (ATIN) in 14 out of 16 renal biopsies as the most common morphological result. The gene discussed is PDCD1; the disease is lupus nephritis.