Fenretinide decreases (A) cell count and (B) cell viability: Endometriotic cells were treated with vehicle (dimethyl sulfoxide [DMSO]) and increasing concentration of fenretinide (5, 10, 15, 20 µmol/L) for 6 days. Cell count was done using Bio-rad cell counter, and the viability was measured using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Data are presented as (A) total average cell count and (B) fold change in viability compared to control samples. Results represent the mean ± standard error of the mean (sem) from 6 independent experiments using tissues from different subjects.