The data file contains the (average difference) cell cycle data for 6519 genes. Time points in cell cycle are in the same order as the columns. The cells are mouse embyro fibroblasts. Same cells were used for the two types of analysis -- serum stimulation and HU release. The first seven samples (the first seven columns in the AD matrix) are from the serum stimulation (at 0, 6, 12, 15, 18, 21, and 24 hr following serum stimulation of non-growing cells). The second seven samples (#8-14) are from the HU release (0, 3, 6, 9, 12, 15, and 18 hr following release from an HU block). The HU block arrests cells at the beginning of S phase and allows an examination of cell cycle progression through S phase and into the next cell cycle.