In line with our in vitro results, data from orthotopic BCa models using T24‐CIS cells showed that the R180A and Q275A mutations in Ins‐TACO1, but not the R196A mutation, restored MTCO1 expression levels and cisplatin resistance following TACO1 knockdown (Figure 7G,H; Figure S9R, Supporting Information). This evidence concerns the gene MT-CO1 and in situ carcinoma.