Interestingly, palmitoylation-dependent plasma membrane localization and activation of a second isoform of ESR1, designated ER36 (36 kDa), has been described in triple-negative breast cancer cells that are generally considered to be negative for all receptors (ESR1, ERBB2, and PR).62 E2-induced ER36 was found to mediate anti-apoptotic effects in cells treated with the chemotherapeutic taxol, through two signaling pathways (Figure 2b). This evidence concerns the gene ESR1 and triple-negative breast carcinoma.