In this review, 5.7% (n = 4) of the studies that tested carvacrol or thymol showed that they were able to increase in vitro JNK phosphorylation in colon cancer (Fan et al., 2015; Chauhan et al., 2018), choriocarcinoma (Lim et al., 2019) and bladder cancer (Li et al., 2017). Here, MAPK8 is linked to urinary bladder cancer.