TP53 and lip and oral cavity carcinoma: In line with these observations, exposure of oral cancer cells to BITC, (7.5 μM) and PEITC (10 μM) also caused increased production of oxidative stress leading to GSH depletion, increased expression of serine/threonine protein kinase ATM, Chk2, p53, and p21, while expression of Cdc2, cyclin B1, Mcl-1 and Bcl-2 was suppressed.