The phrase "from unknown origin" is grammatically correct and can be used in written English.
It is typically used to describe something or someone whose original source or development is unknown. Example: The painting was discovered in a remote cave, but its artist remains a mystery, making it a piece of art from unknown origin.
Nottebaert et al. [2] found lung carcinomas to be responsible for 52%% of 51 cases of bone lesions from unknown origin, while they accounted for only 7%% of bone metastases with a diagnosed primary.
From an analysis of the Swedish Cancer Registry from 1993 to 2008, Hemminki et al. [13] found that patients with metastases from unknown origin diagnosed in the bone mostly died of lung cancer.
For example, Roh et al. [ 6] have shown that sensitivity of FDG PET/CT (87.5%) was significantly higher (p = 0.016) than that of CT alone (43.7%) in detecting primary tumors in 44 patients presenting with cervical metastases from unknown origin.
Twenty-six patients (25.2%) had pancreatic NET, 27 (26.2%) had gastrointestinal NET, 2 (1.9%) had lung NET, 28 (27.2%) had NET from other sites, and 20 (19.4%) had NET from unknown origin.
In addition, the quite common practice to use reproductive material from unknown origin might have resulted in a significant proportion of re-implanted stocks poorly adapted to site conditions.
Although cystitis is usually caused by bacterial infection, it can also be caused by noninfectious conditions such as carcinoma in situ, bladder cancer, and bladder stone or it can even emerge from unknown origin as in interstitial cystitis [ 27].
This manual procedure also permitted removal of additional artifacts (such as ground clutter, bird or airplane echoes, and other contaminations from unknown origins) as far as possible.
PROBLEM: Cell-in-cell structures can arise in PDAC from unknown origins and mechanisms.
The sequences that contribute to the generation of the chimeric ORFs are typically derived from coding and noncoding regions of existing genes, but are occasionally from unknown origins.
Accessions were from different geographical origins: 3 from Africa, 7 from America, 17 from Central Asia, 90 from Europe (4 from Central Europe, 74 from Spain and 13 from other southern European regions), 3 from the Far East and India, 12 from Middle East and the remaining 14 from unknown origins (see Additional file 1).
Genetic data suggest that P. ramorum is an exotic pathogen in Europe and in North America, introduced in the nursery trade of both continents from unknown origins at least four times independently as indicated by the presence of four clonal lineages: EU1, EU2, NA1, and NA2 (reviewed in Garbelotto and Hayden 2012).
