Array Comparative Genomic Hybridization (CGH) profiling of Oral Leukoplakia (OPL) and early stage Oral Squamous Cell Carcinoma (OSCC) was performed to delineate candidate non-random chromosomal loci associated with disease progression and clinico-pathological parameters. The array CGH hybridizations were performed for 24 OPL and 38 OSCC samples with pooled gender matched controls. All tissue samples were collected after obtaining written informed consent. Overall design: Agilent two-color CGH experiment,Organism: Agilent-21764 Human Genome CGH Microarray 105A (G4412A), Labeling kit: Agilent Sure tag DNA labeling kit (Agilent Technologies, 5190-3400).