TP53 and tongue cancer: Atula et al. [113] have studied p53 mutations and protein expression in tongue cancer, and found mutations in 54% of the samples by means of single-stranded conformation polymorphism (SSCP) analysis, which correlated with tumour size (41% in T1-2 versus 90% in T3-4; Fisher's exact test, P < .01) and grading (75% of grade 2-3 versus 32% of low-grade cancers; chi-squared test, P < .01).