105B was also tested in KYSE180 cells, an ESCC cell line that is known to undergo transcriptional regulation by BRD4 and BRDT and expresses MAGEA11.30,29 105B degraded BRD4 with a DC50 of 40 ± 11 nM and a Dmax of 70 ± 3 % in KYSE180 cells (Figure 3b; Supplementary Figure S4). Here, BRD4 is linked to esophageal squamous cell carcinoma.