While BCKDH and HACL1 are (as indicated above) TPP-dependent enzymes, their activity is rarely reported in the context of thiamine deficiency, with the majority of studies focusing on TKT and PDH or αKGDH as indicators of oxidative stress (TKT) and mitochondrial dysfunction (PDH or αKGDH). This evidence concerns the gene PPM1K and Thiamine deficiency.