In Government Service Insurance System v. Court of Appeals,   this Court comprehensively discussed the principles and policies of the existing compensation law, P.D. No. 626, as amended, viz: [9]   At the outset, certain basic postulates governing employees compensation benefits under P.D. No. 626 need be reviewed.  First, said Decree abandoned the presumption of compensability and the theory of aggravation under the Workmens Compensation Act.  Second, for the sickness and resulting disability or death to be compensable, the claimant must prove either of two (2) things:  (a) that the sickness was the result of an occupational disease listed under Annex A of the Rules on Employees Compensation; or   (b) if the sickness is not so listed, that the risk of contracting the disease was increased by the claimants working conditions.   Third, the claimant must prove this causal relation between the ailment and working conditions by substantial evidence , since the proceeding is taken before the ECC, an administrative or quasi-judicial body. Within the field of administrative law, while strict rules of evidence are not applicable to quasi-judicial proceedings, nevertheless, in adducing evidence constitutive of substantial evidence, the basic rule that mere allegation is not evidence cannot be disregarded.  Finally, in case of doubt in construction and interpretation of social legislation statutes, the liberality of the law in favor of the working man and woman prevails in light of the Constitutions social justice policy.   On the other side of the coin, however, there is a competing, yet equally vital interest to heed in passing upon undeserving claims for compensation.  It is well to remember that if diseases not intended by the law to be compensated are inadvertently or recklessly included, the integrity of the State Insurance Fund is endangered.  Compassion for the victims of diseases not covered by the law ignores the need to show a greater concern for the trust fund to which the tens of millions of workers and their families look to for compensation whenever covered accidents, diseases and deaths occur. This stems from the development in the law that no longer is the poor employee still arrayed against the might and power of his rich corporate employer, hence the necessity of affording all kinds of favorable presumptions to the employee.   This reasoning is no longer good policy.   It is now the trust fund and not the employer which suffers if benefits are paid to claimants who are not entitled under the law. The employer joins the employee in trying to have their claims approved.  The employer is spared the problem of proving a negative proposition that the disease was not caused by employment.   Moreover, the new system instituted by the new law