PDHB and intervertebral disk degenerative disorder: Firstly, a total of 8 significant cuproptosis modulators were screened from 16 cuproptosis modulators via differential expression analysis between controls and IDD cases, which were selected as diagnostic cuproptosis modulators (LIPT1, DLAT, PDHB, GCSH, DLST, ATP7A, ATP7B and MTF1) based on an established RF model to predict the occurrence of IDD.