preferred_name: Addition of the third nucleotide on the nascent transcript (Xenopus tropicalis)
preferred_name_lc: addition of the third nucleotide on the nascent transcript (xenopus tropicalis)
label: Addition of the third nucleotide on the nascent transcript (Xenopus tropicalis)
label_lc: addition of the third nucleotide on the nascent transcript (xenopus tropicalis)