All 7 PDX SCLC lines exhibited greater than 60% PARP1-positive area (between 64 ± 6% PARP1-positive area for JHU-LX92 and 86 ± 3% PARP1-positive area for JHU-LX102), while all organs, except for spleen, exhibited lower than 5% PARP1-positive area (Supplementary Fig. 4), emphasizing the quantitative difference in PARP1 density for binding of PARP1 targeted agents. The gene discussed is PARP1; the disease is small cell lung carcinoma.