Next, AS of sarcoplasmic/ER calcium ATPase 1 (SERCA1) and insulin receptor (INSR) transcripts, previously found to be defective for exon inclusion in DM1 myogenic cells,25 was analysed by qRT‐PCR in untreated and DOX‐treated DM1 cells, compared with CT. Here, INSR is linked to myotonic dystrophy type 1.