To gain insight into the role of Lys120 integrity in the recognition of specific RE sequences, we performed a chromatin-immunoprecipitation experiment and analyzed genome-wide occupancy of conditionally-expressed wild-type (WT) and K120R forms of p53 in the isogenic human H1299 lung cancer cell line that is null for endogenous p53 (Fig. 1a). The gene discussed is TP53; the disease is lung carcinoma.