MAPK8 and osteosarcoma: Phenoxodiol blocks the activation of SPHK1, and anthracycline is then able to promote ceramide accumulation in osteosarcoma cells, mediate the activation of the apoptosis signal‐regulating kinase 1 (ASK1)/c‐Jun N‐terminal kinase (JNK) pathway and negatively regulate Akt activity, suggesting that the inhibition of SPHK1 may restore the sensitivity of osteosarcoma to anthracycline.122