48h BC spheroids generated from E2-treated and non-treated MCF7 cells were exposed to DETA/NO for 24h and then either fixed within the HMC array and stained by anti-ERα Abs for imaging-based analysis or recovered from the array, pooled and analyzed using reverse transcription polymerase chain reaction (RT-PCR) and western blotting. The gene discussed is ESR1; the disease is breast cancer.