NR4A1 and breast cancer: A total of twenty-six compounds of furfuryl or benzyl (S)-2-(substituted arylmethyl)-1-oxo-1,2,3,4-tetrahydropyrazino[1,2-a]indole-3-carboxamide analogs were synthesized and evaluated for cytotoxic activity against the hormone receptor-positive breast cancer cell line (MCF-7) and the EGFR-overexpressed TNBC cell line (MDA-MB-468), using a dose-dependent MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, as shown in Table 1.