On the accuracy of splicing
The spliceosome is a very complex structure containing up to one hundred proteins and five different RNAs. The substrate of the reaction is a long RNA molecule and the transesterification reactions catalyzed by the spliceosome require the bringing together of sites that may be thousands of nucleotides apart. All biochemical reactions are associated with known error rates and the more complicated the reaction the higher the error rate. Therefore, it is not surprising that the splicing reaction catalyzed by the spliceosome has a significant error rate even though there are spliceosome accessory factors that suppress the accidental cleavage of cryptic splice sites.Under ideal circumstances, the splicing reaction is likely to be 99.999% accurate (error rate of 10−5) and the correct exons will be joined and the correct intron will be deleted. However, these ideal conditions require very close matches to the best splice site sequences and the absence of any competing cryptic splice site sequences within the introns and those conditions are rarely met in large eukaryotic genes that may cover more than 40 kilobase pairs. Recent studies have shown that the actual error rate can be considerably higher than 10−5 and may be as high as 2% or 3% errors (error rate of 2 or 3 x 10−2) per gene. Additional studies suggest that the error rate is no less that 0.1% per intron.
Epidemiology
Lipid pneumonia has been known to occur in underwater divers after breathing poorly filtered air supplied by a surface compressor lubricated by mineral oil. History
Laughlen first described lipid pneumonia in 1925 with infants that inhaled oil droplets. It is a condition that has been seen as an occupational risk for commercial diving operations but documented cases are rare. References
Further reading
Spickard, Anderson; Hirschmann, JV (28 March 1994). "Exogenous Lipoid Pneumonia". Archives of Internal Medicine. 154 (6): 686–92. doi:10.1001/archinte.1994.00420060122013. PMID 8129503. Betancourt, SL; Martinez-Jimenez, S; Rossi, SE; Truong, MT; Carrillo, J; Erasmus, JJ (January 2010). "Lipoid pneumonia: spectrum of clinical and radiologic manifestations". AJR. American Journal of Roentgenology. 194 (1): 103–9. doi:10.2214/ajr.09.3040. PMID 20028911. External links

Gross pathology specimen from the University of Utah