siRNA on SEL1L exon 12 and scrambled control (C) (panel A) showed the down‐modulation of the different SEL1L variants: 100 kDa isoform, corresponding to the ER‐resident variant SEL1LA (SEL1LA‐p100), 70/78 kDa isoform (SEL1L‐p70/80) with a predominant nuclear location, and 38 kDa secreted variant (SEL1L‐p38), generally expressed in tumour cells. This evidence concerns the gene SEL1L and neoplasm.