CDK4 and breast cancer: In overall, similar to breast cancer, somatic ERBB2 alterations occur in 40% gallbladder samples (10 of 25) either through mutations or over expression.39, 40 Interestingly, copy number analysis using cghMCR software identified EGFR amplification with a highest Segment Gain Or Loss (SGOL) score of 18 (Fig. 1a), as reported earlier.18 Genomic amplifications were also observed at loci harboring CDK4, MDM4, CCND1, CCNE1, MYC, STK11 and BRD3, and deletions in FHIT, SMAD4, TRIM33 and APC.