STARD7 and breast cancer: Another reason may come from the role of STARD7 in Coenzyme Q synthesis.[9] Coenzyme synthesis, a multi‐step process, requires SAM as a co‐factor for both O‐ and C2‐methylations.[39] Therefore, SAMs accumulation may be an indirect consequence of a defective Coenzyme Q synthesis seen in breast cancer lacking STARD7.