Intriguingly, it has been reported that SOD2 could reverse the conversion of CD44− cells to CD44+ cells, suggesting that ROS may be involved in the transformation of cancer stem cell-like characteristics.136 It is worth noting that a CD44 variant (CD44v) could protect cancer cells against excessive ROS by stabilizing the cystine-glutamate transporter xCT, which contributes to chemotherapy resistance,137,138 suggesting that targeting CD44v or xCT may sensitize cancer cells to chemotherapy. The gene discussed is SOD2; the disease is cancer.