TWIST1 and breast cancer: In humans, germline mutations in the TWIST1 oncogene have been suggested to predispose to breast cancer [60], however, a study of 34 feline mammary carcinomas only identified two intronic germline variants (535delG and 460C >T, in 3 and 4 cases, respectively) and noted there was no association between these alterations and TWIST1 mRNA levels [55].