In Nucleic Acids Research this week, Prathima Iengar from the Indian Institute of Science in Bangalore discusses substitutions and indels in cancer genes. She analyzed such cancer-related mutations found in the COSMIC database and found that "the most frequent substitutions were c→t, g→a, g→t, and the most frequent codon changes were to termination codons." In addition, she notes that deletions are more common than insertions and most indels cause frameshifts.