{
  "species": "At",
  "system": "leaf",
  "replicate": 1,
  "barcodes": 214433,
  "promoters": 12082,
  "train_promoters": 9673,
  "test_promoters": 2409,
  "heldout_within_promoter_r2": 0.00954301149905501,
  "first_base_ACG_span": 0.025554631264186195,
  "first_base_counts": {
    "A": 90556,
    "C": 75970,
    "G": 47903,
    "T": 4
  },
  "note": "Observational OLS after within-promoter centering; >=5 counts in both DNA and RNA. No mechanistic attribution. ACG first-base span excludes the design-disallowed T."
}