preferred_name: choline(in) + H(+)(in) <=> choline(out) + H(+)(out)
preferred_name_lc: choline(in) + h(+)(in) <=> choline(out) + h(+)(out)
label: choline(in) + H(+)(in) <=> choline(out) + H(+)(out)
label_lc: choline(in) + h(+)(in) <=> choline(out) + h(+)(out)